backing out the change in external_processor.proto as we will change…

… it completely anyway

Signed-off-by: Yanjun Xiang <[email protected]>

api/envoy/service/ext_proc/v3/external_processor.proto

@@ -285,9 +285,9 @@ message CommonResponse {
   // along with the CONTINUE_AND_REPLACE status.
   config.core.v3.HeaderMap trailers = 4;
 
-  // Clear the route cache for the downstream client request. This is necessary
-  // if the remote server modified headers that are used to calculate the route.
-  // This field is ignored for the upstream response message.
+  // Clear the route cache for the current request.
+  // This is necessary if the remote server
+  // modified headers that are used to calculate the route.
   bool clear_route_cache = 5;
 }