RenameRevertException: Add missing serialVersionUID

Fix the corresponding Eclipse warning.

Change-Id: I5444645a11c28391c0d860c1c4cc3bd1d570929e
diff --git a/src/main/java/com/googlesource/gerrit/plugins/renameproject/RenameRevertException.java b/src/main/java/com/googlesource/gerrit/plugins/renameproject/RenameRevertException.java
index fcb6021..0cb6256 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/renameproject/RenameRevertException.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/renameproject/RenameRevertException.java
@@ -17,6 +17,8 @@
 
 /** Add cause for exception during revert operation */
 public class RenameRevertException extends OrmException {
+  private static final long serialVersionUID = 1L;
+
   public RenameRevertException(Throwable revertException, Throwable cause) {
     super(
         "Failed to revert after failed rename. Revert cause: " + cause.getMessage(),