DefaultFileSystemMonitor produces NPE during connector start

[madoed]

Describe the bug
We are using FP to read CSV file s from S3 to Kafka. After some time of work connector stopped to accept new files and after restarting of connector we are got next error stacktrace:

java.lang.NullPointerException 
io.streamthoughts.kafka.connect.filepulse.fs.DefaultFileSystemMonitor.recoverPreviouslyCompletedSources(DefaultFileSystemMonitor.java:192) 
 io.streamthoughts.kafka.connect.filepulse.fs.DefaultFileSystemMonitor.<init>(DefaultFileSystemMonitor.java:183) 
 io.streamthoughts.kafka.connect.filepulse.source.FilePulseSourceConnector.start(FilePulseSourceConnector.java:125) 
 org.apache.kafka.connect.runtime.WorkerConnector.doStart(WorkerConnector.java:184) 
 org.apache.kafka.connect.runtime.WorkerConnector.start(WorkerConnector.java:209) 
 org.apache.kafka.connect.runtime.WorkerConnector.doTransitionTo(WorkerConnector.java:348) 
 org.apache.kafka.connect.runtime.WorkerConnector.doTransitionTo(WorkerConnector.java:331) 
 org.apache.kafka.connect.runtime.WorkerConnector.doRun(WorkerConnector.java:140) 
 org.apache.kafka.connect.runtime.WorkerConnector.run(WorkerConnector.java:117) 
 java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515) 
 java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264) 
 java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) 
 java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) 
 java.base/java.lang.Thread.run(Thread.java:829)

Looks like something went wrong during processing file and I guess file was deleted from S3.Also it could be related to #457. Because our auto tests may produce empty csv file.

To Reproduce
Unfortunately I didn't find a way to reproduce it locally.
Expected behavior
Successful recover after connector restart.

Screenshots
N/A

Additional context
We are using FP 2.7.0
Here our configuration:

{
    "name": "<connector_name>",
    "connector.class": "io.streamthoughts.kafka.connect.filepulse.source.FilePulseSourceConnector",
    "topic": "<output_topic>",
    "tasks.max": "1",
    "fs.listing.class": "io.streamthoughts.kafka.connect.filepulse.fs.AmazonS3FileSystemListing",
    "fs.listing.interval.ms": "10000",
    "fs.listing.filters": "io.streamthoughts.kafka.connect.filepulse.fs.filter.RegexFileListFilter",
    "file.filter.regex.pattern": ".*\\.csv$",
    "aws.access.key.id": "<access_key>",
    "aws.secret.access.key": "<secret_key>",
    "aws.s3.service.endpoint": "<s3_url>",
    "aws.s3.bucket.name": "<some_bucket_name>",
    "aws.s3.bucket.prefix": "incoming",
    "fs.cleanup.policy.class": "io.streamthoughts.kafka.connect.filepulse.fs.clean.AmazonS3MoveCleanupPolicy",
    "fs.cleanup.policy.move.success.aws.prefix.path": "processed",
    "fs.cleanup.policy.move.failure.aws.prefix.path": "failed",
    "tasks.reader.class": "io.streamthoughts.kafka.connect.filepulse.fs.reader.AmazonS3RowFileInputReader",
    "offset.attributes.string": "name+lastModified",
    "filters": "ParseCSVLine",
    "filters.ParseCSVLine.type": "io.streamthoughts.kafka.connect.filepulse.filter.CSVFilter",
    "filters.ParseCSVLine.columns": "offerId:LONG;clientId:STRING;clientType:INTEGER",
    "filters.ParseCSVLine.trimColumn": "true",
    "filters.ParseCSVLine.separator": ";",
    "value.connect.schema": "{\"name\":\"ru.tinkoff.target.experiments.avro.client.ClientOfferAvro\",\"type\":\"STRUCT\",\"isOptional\":false,\"fieldSchemas\":{\"clientId\":{\"type\":\"STRING\",\"isOptional\":false},\"offerId\":{\"type\":\"INT64\",\"isOptional\":false},\"clientType\":{\"type\":\"INT32\",\"isOptional\":false}},\"version\":1}",
    "tasks.file.status.storage.class": "io.streamthoughts.kafka.connect.filepulse.state.KafkaFileObjectStateBackingStore",
    "tasks.file.status.storage.topic": "<status_topic>",
    "tasks.file.status.storage.bootstrap.servers": "broker:29092",
    "key.converter": "org.apache.kafka.connect.storage.StringConverter",
    "value.converter": "io.confluent.connect.avro.AvroConverter",
    "value.converter.schema.registry.url": "http://schema-registry:8081"
}

[fhussonnois]

🎉 This issue has been resolved in v2.13.0 (Release Notes)

[madoed]

@fhussonnois btw could you please also update version of connector at confluent hub?
For now only 2.10.0 version is available there