Fix CID 1164567 (Dereference after null check)

It looks like the check cblob_ptr != nullptr is not needed.
If cblob_ptr were NULL, we would have seen crashes in compute_bounding_box.

Signed-off-by: Stefan Weil <sw@weilnetz.de>

Author: stweil

src/ccstruct/blobbox.cpp

@@ -103,7 +103,7 @@ void BLOBNBOX::merge(                    //merge blobs
 // Merge this with other, taking the outlines from other.
 // Other is not deleted, but left for the caller to handle.
 void BLOBNBOX::really_merge(BLOBNBOX* other) {
-  if (cblob_ptr != nullptr && other->cblob_ptr != nullptr) {
+  if (other->cblob_ptr != nullptr) {
     C_OUTLINE_IT ol_it(cblob_ptr->out_list());
     ol_it.add_list_after(other->cblob_ptr->out_list());
   }