nghttpx: Deprecate --backend-http2-connections-per-worker option

src/shrpx.cc

@@ -1352,15 +1352,6 @@ Performance:
               accepts.  Setting 0 means unlimited.
               Default: )" << get_config()->conn.upstream.worker_connections
       << R"(
-  --backend-http2-connections-per-worker=<N>
-              Set   maximum   number   of  backend   HTTP/2   physical
-              connections  per  worker.   If  pattern is  used  in  -b
-              option, this limit is applied  to each pattern group (in
-              other  words, each  pattern group  can have  maximum <N>
-              HTTP/2  connections).  The  default  value  is 0,  which
-              means  that  the value  is  adjusted  to the  number  of
-              backend addresses.  If pattern  is used, this adjustment
-              is done for each pattern group.
   --backend-http1-connections-per-host=<N>
               Set   maximum  number   of  backend   concurrent  HTTP/1
               connections per origin host.   This option is meaningful

src/shrpx_config.cc

@@ -2077,8 +2077,8 @@ int parse_config(const char *opt, const char *optarg,
 
     return 0;
   case SHRPX_OPTID_BACKEND_HTTP2_CONNECTIONS_PER_WORKER:
-    return parse_uint(&mod_config()->http2.downstream.connections_per_worker,
-                      opt, optarg);
+    LOG(WARN) << opt << ": deprecated.";
+    return 0;
   case SHRPX_OPTID_FETCH_OCSP_RESPONSE_FILE:
     mod_config()->tls.ocsp.fetch_ocsp_response_file = optarg;
 

src/shrpx_config.h

@@ -485,7 +485,6 @@ struct Http2Config {
     nghttp2_session_callbacks *callbacks;
     size_t window_bits;
     size_t connection_window_bits;
-    size_t connections_per_worker;
   } downstream;
   struct {
     ev_tstamp stream_read;