Fix mistake in method called

Author: Raihaan Shouhell

src/main/java/hudson/plugins/git/RevisionParameterAction.java

@@ -196,7 +196,7 @@ public void foldIntoExisting(Queue.Item item, Queue.Task owner, List<Action> oth
         if(combineCommits) {
             //because we cannot modify the commit in the existing action remove it and add self
             // or no CauseAction found, so add a copy of this one
-            item.addAction(this);
+            item.replaceAction(this);
         }
     }