Fix eclipse warnings

Change-Id: I4f487f18684a635e9e7dab3e9cc12baa76b72e18
diff --git a/owners-autoassign/src/main/java/com/vmware/gerrit/owners/common/ReviewerManagerException.java b/owners-autoassign/src/main/java/com/vmware/gerrit/owners/common/ReviewerManagerException.java
index 9bed4c8..2425514 100644
--- a/owners-autoassign/src/main/java/com/vmware/gerrit/owners/common/ReviewerManagerException.java
+++ b/owners-autoassign/src/main/java/com/vmware/gerrit/owners/common/ReviewerManagerException.java
@@ -17,6 +17,8 @@
 package com.vmware.gerrit.owners.common;
 
 public class ReviewerManagerException extends Exception {
+  private static final long serialVersionUID = 1L;
+
   public ReviewerManagerException(String message) {
     super(message);
   }