revert search timeout, switch cluster event timeout to 429

Author: rjernst

server/src/main/java/org/elasticsearch/cluster/metadata/ProcessClusterEventTimeoutException.java

@@ -28,6 +28,6 @@ public ProcessClusterEventTimeoutException(StreamInput in) throws IOException {
 
     @Override
     public RestStatus status() {
-        return RestStatus.SERVICE_UNAVAILABLE;
+        return RestStatus.TOO_MANY_REQUESTS;
     }
 }

server/src/main/java/org/elasticsearch/search/query/SearchTimeoutException.java

@@ -31,6 +31,6 @@ public SearchTimeoutException(StreamInput in) throws IOException {
 
     @Override
     public RestStatus status() {
-        return RestStatus.TOO_MANY_REQUESTS;
+        return RestStatus.GATEWAY_TIMEOUT;
     }
 }