CommitValidators: Debug log when commit validation exception occurs

Change-Id: I2b26d59015da08136679b3d8e762a9cc2335ec1b
Signed-off-by: David Pursehouse <dpursehouse@collab.net>
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/git/validators/CommitValidators.java b/gerrit-server/src/main/java/com/google/gerrit/server/git/validators/CommitValidators.java
index b38f797..dc998d6 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/git/validators/CommitValidators.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/git/validators/CommitValidators.java
@@ -174,6 +174,7 @@
         messages.addAll(commitValidator.onCommitReceived(receiveEvent));
       }
     } catch (CommitValidationException e) {
+      log.debug("CommitValidationException occurred: {}", e.getFullMessage(), e);
       // Keep the old messages (and their order) in case of an exception
       messages.addAll(e.getMessages());
       throw new CommitValidationException(e.getMessage(), messages);