Add missing @Override annotations

And remove unnecessary suppression of warning for unused parameter
in overridden method.

Change-Id: I7db95dee276f44b4245d8f7ca00df761e687a350
diff --git a/src/main/java/com/googlesource/gerrit/plugins/manager/TokenReplaceOutputStream.java b/src/main/java/com/googlesource/gerrit/plugins/manager/TokenReplaceOutputStream.java
index 2c5976b..4eb643b 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/manager/TokenReplaceOutputStream.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/manager/TokenReplaceOutputStream.java
@@ -97,9 +97,11 @@
     flush();
   }
 
-  public void setWriteListener(@SuppressWarnings("unused") WriteListener writeListener) {
+  @Override
+  public void setWriteListener(WriteListener writeListener) {
   }
 
+  @Override
   public boolean isReady() {
     return true;
   }