Thesaurus / Date parsing fix.

https://github.com/geonetwork/core-geonetwork/pull/6972/files#diff-c7548d94bdb4268915f50f66df5a90f1f7868e4fb1de2f3d2938397e202aaf2fR1057
added month and year format support. This was resolving thesaurus date
to the last matching format ie. 1st January for the default date.

This can be tested using regions thesaurus which will contains 2 dates
for the thesaurus block.

core/src/main/java/org/fao/geonet/kernel/Thesaurus.java

@@ -1064,12 +1064,11 @@ private Date parseThesaurusDate(Element dateEl) {
 
         StringBuffer errorMsg = new StringBuffer("Error parsing the thesaurus date value: ");
         errorMsg.append(dateVal);
-        boolean success = false;
 
         for (SimpleDateFormat df : dfList) {
             try {
                 thesaurusDate = df.parse(dateVal);
-                success = true;
+                return thesaurusDate;
             } catch (Exception ex) {
                 // Ignore the exception and try next format
                 errorMsg.append("\n  * with format: ");
@@ -1079,11 +1078,9 @@ private Date parseThesaurusDate(Element dateEl) {
             }
         }
         // Report error if no success
-        if (!success) {
-            errorMsg.append("\nCheck thesaurus date in ");
-            errorMsg.append(this.fname);
-            Log.error(Geonet.THESAURUS_MAN, errorMsg.toString());
-        }
+        errorMsg.append("\nCheck thesaurus date in ");
+        errorMsg.append(this.fname);
+        Log.error(Geonet.THESAURUS_MAN, errorMsg.toString());
         return thesaurusDate;
     }