CodeOwnerSubmitRule: Only increase rule error metric if RULE_ERROR is returned

Signed-off-by: Edwin Kempin <ekempin@google.com>
Change-Id: If65cafa15db03f9f1b87ba47e15c43ebf8fa5415
diff --git a/java/com/google/gerrit/plugins/codeowners/backend/CodeOwnerSubmitRule.java b/java/com/google/gerrit/plugins/codeowners/backend/CodeOwnerSubmitRule.java
index e69616d..df96cc4 100644
--- a/java/com/google/gerrit/plugins/codeowners/backend/CodeOwnerSubmitRule.java
+++ b/java/com/google/gerrit/plugins/codeowners/backend/CodeOwnerSubmitRule.java
@@ -146,9 +146,10 @@
         }
       }
       errorMessage += ".";
-      codeOwnerMetrics.countCodeOwnerSubmitRuleErrors.increment(cause);
 
       if (isRuleError) {
+        codeOwnerMetrics.countCodeOwnerSubmitRuleErrors.increment(cause);
+
         logger.atWarning().log(errorMessage);
         return Optional.of(ruleError(errorMessage));
       }