File jc-1.2.1-optional-tcp-protocol.patch of Package jc

diff -Ndurp jc-1.2.1/src/jc_app.erl jc-1.2.1-optional-tcp-protocol/src/jc_app.erl
--- jc-1.2.1/src/jc_app.erl	2016-09-07 15:51:56.000000000 +0300
+++ jc-1.2.1-optional-tcp-protocol/src/jc_app.erl	2018-03-01 13:27:14.411755710 +0200
@@ -29,13 +29,12 @@
 
 start(_StartType, _StartArgs) ->
     ok = jc_cluster:init(),
-    Port = application:get_env(jc, protocol_port, 5555),
-    {ok, _} = ranch:start_listener(jc_proto, 
-				   100,
-				   ranch_tcp, 
-				   [{port, Port}], 
-				   jc_protocol, [Port]),
-    lager:info("tcp, protocol listener is up and listening on port: ~p", [Port]), 
+    case application:get_env(jc, protocol_port) of
+        {ok, Port} when is_integer(Port), Port > 0 ->
+	    {ok, _} = ranch:start_listener(jc_proto, 100, ranch_tcp, [{port, Port}], jc_protocol, [Port]),
+	    lager:info("tcp, protocol listener is up and listening on port: ~p", [Port]);
+	_ -> ok
+    end,
     case jc_sup:start_link() of
 	{ok, Pid} ->
 	    {ok, Pid};