fix(jans-auth-server): corrected regression made in token request #2921 (#2922)

Fixes test failures on jenkins

Author: yuriyz

jans-auth-server/client/src/main/java/io/jans/as/client/ClientAuthnEnabler.java

@@ -11,6 +11,7 @@
 
 import jakarta.ws.rs.client.Invocation.Builder;
 import jakarta.ws.rs.core.Form;
+import org.apache.commons.lang.StringUtils;
 
 
 /**
@@ -45,10 +46,12 @@ public void exec(ClientAuthnRequest request) {
         if (request.getAuthenticationMethod() == AuthenticationMethod.CLIENT_SECRET_JWT ||
                 request.getAuthenticationMethod() == AuthenticationMethod.PRIVATE_KEY_JWT) {
             requestForm.param("client_assertion_type", ClientAssertionType.JWT_BEARER.toString());
-            if (request.getClientAssertion() != null) {
-                requestForm.param("client_assertion", request.getClientAssertion());
+
+            final String clientAssertion = request.getClientAssertion();
+            if (clientAssertion != null) {
+                requestForm.param("client_assertion", clientAssertion);
             }
-            if (request.getAuthUsername() != null && !request.getAuthUsername().isEmpty()) {
+            if (StringUtils.isNotBlank(request.getAuthUsername())) {
                 requestForm.param("client_id", request.getAuthUsername());
             }
         }

jans-auth-server/client/src/main/java/io/jans/as/client/TokenRequest.java

@@ -38,7 +38,6 @@ public class TokenRequest extends ClientAuthnRequest {
     private String codeVerifier;
     private String authReqId;
     private String deviceCode;
-    private String audience;
     private String subjectToken;
     private String subjectTokenType;
     private String actorToken;
@@ -109,16 +108,6 @@ public void setRequestedTokenType(String requestedTokenType) {
         this.requestedTokenType = requestedTokenType;
     }
 
-    @Override
-    public String getAudience() {
-        return audience;
-    }
-
-    @Override
-    public void setAudience(String audience) {
-        this.audience = audience;
-    }
-
     /**
      * Returns the grant type.
      *
@@ -325,7 +314,7 @@ public String getQueryString() {
         builder.append("refresh_token", refreshToken);
         builder.append("auth_req_id", authReqId);
         builder.append("device_code", deviceCode);
-        builder.append("audience", audience);
+        builder.append("audience", getAudience());
         builder.append("subject_token", subjectToken);
         builder.append("subject_token_type", subjectTokenType);
         builder.append("actor_token", actorToken);
@@ -360,8 +349,8 @@ public Map<String, String> getParameters() {
         if (username != null && !username.isEmpty()) {
             parameters.put("username", username);
         }
-        if (StringUtils.isNotBlank(audience)) {
-            parameters.put("audience", audience);
+        if (StringUtils.isNotBlank(getAudience())) {
+            parameters.put("audience", getAudience());
         }
         if (StringUtils.isNotBlank(subjectToken)) {
             parameters.put("subject_token", subjectToken);