Revert ac0bd74f6f9716e3a44d1412f795317c30ca770a (#4295)

This reverts commit ac0bd74. But leaves the API changes as 'not implemented' in order to not scramble the proto field.

#4073 had a bug. The cause has been identified, and a fix PR is forthcoming. However, in the meantime, we want to leave master clean.

Mirrored from https://github.com/envoyproxy/envoy @ 9d094e590f814485b53c7e46a4fb1066a71c36d3

envoy/config/filter/accesslog/v2/accesslog.proto

@@ -162,6 +162,6 @@ message ResponseFlagFilter {
   // This field is optional. If it is not specified, then any response flag will pass
   // the filter check.
   repeated string flags = 1 [(validate.rules).repeated .items.string = {
-    in: ["LH", "UH", "UT", "LR", "UR", "UF", "UC", "UO", "NR", "DI", "FI", "RL", "UAEX", "RLSE"]
+    in: ["LH", "UH", "UT", "LR", "UR", "UF", "UC", "UO", "NR", "DI", "FI", "RL", "UAEX"]
   }];
 }

envoy/config/filter/http/rate_limit/v2/rate_limit.proto

@@ -35,6 +35,7 @@ message RateLimit {
   // set, this defaults to 20ms.
   google.protobuf.Duration timeout = 4 [(gogoproto.stdduration) = true];
 
+  // [#not-implemented-hide:] Hide from docs.
   // The filter's behaviour in case the rate limiting service does
   // not respond back. When it is set to true, Envoy will not allow traffic in case of
   // communication failure between rate limiting service and the proxy.

envoy/config/filter/network/rate_limit/v2/rate_limit.proto

@@ -27,6 +27,7 @@ message RateLimit {
   // set, this defaults to 20ms.
   google.protobuf.Duration timeout = 4 [(gogoproto.stdduration) = true];
 
+  // [#not-implemented-hide:] Hide from docs.
   // The filter's behaviour in case the rate limiting service does
   // not respond back. When it is set to true, Envoy will not allow traffic in case of
   // communication failure between rate limiting service and the proxy.

envoy/data/accesslog/v2/accesslog.proto

@@ -185,6 +185,7 @@ message ResponseFlags {
   // Indicates if the request was deemed unauthorized and the reason for it.
   Unauthorized unauthorized_details = 13;
 
+  // [#not-implemented-hide:] Hide from docs.
   // Indicates that the request was rejected because there was an error in rate limit service.
   bool rate_limit_service_error = 14;
 }