Expect user to close connection abruptly

When waiting for input from socket, expect not only a valid outcome,
but also the client getting bored and closing the connection without
any message being sent.Log an info message when that happens,but do
not make it an error.

Also, only use hyphens for headers sent to registry server.

apps/epp_proxy/src/epp_tls_worker.erl

@@ -124,7 +124,6 @@ read_length(Socket) ->
             LengthToReceive = epp_util:frame_length_to_receive(Length),
             {ok, LengthToReceive};
         {error, Reason} ->
-            lager:error("Error: ~p~n", [Reason]),
             {error, Reason}
     end.
 
@@ -133,7 +132,6 @@ read_frame(Socket, FrameLength) ->
         {ok, Data} ->
             {ok, Data};
         {error, Reason} ->
-            lager:error("Error: ~p~n", [Reason]),
             {error, Reason}
     end.
 
@@ -149,31 +147,34 @@ write_line(Socket, Line) ->
 
 %% First, listen for 4 bytes, then listen until the declared length.
 %% Return the frame binary at the very end.
+%% If the client closes connection abruptly, then kill the process
 frame_from_socket(Socket, State) ->
     Length = case read_length(Socket) of
         {ok, Data} ->
             Data;
-        {error, _Details} ->
-            {stop, normal, State}
+        {error, closed} ->
+            log_and_exit(State)
         end,
 
     Frame = case read_frame(Socket, Length) of
         {ok, FrameData} ->
             FrameData;
-        {error, _FrameDetails} ->
-            {stop, normal, State}
+        {error, closed} ->
+            log_and_exit(State)
         end,
     Frame.
 
+log_and_exit(State) ->
+    lager:info("Client closed connection: [~p]~n", [State]),
+    exit(normal).
+
 %% Extract state info from socket. Fail if you must.
 state_from_socket(Socket, State) ->
     {ok, PeerCert} = ssl:peercert(Socket),
     {ok,  {PeerIp, _PeerPort}} = ssl:peername(Socket),
     {SSL_CLIENT_S_DN_CN, SSL_CLIENT_CERT} =
         epp_certs:headers_from_cert(PeerCert),
-    Headers = [{"SSL_CLIENT_CERT", SSL_CLIENT_CERT},
-               {"SSL_CLIENT_S_DN_CN", SSL_CLIENT_S_DN_CN},
-               {"SSL-CLIENT-CERT", SSL_CLIENT_CERT},
+    Headers = [{"SSL-CLIENT-CERT", SSL_CLIENT_CERT},
                {"SSL-CLIENT-S-DN-CN", SSL_CLIENT_S_DN_CN},
                {"User-Agent", <<"EPP proxy">>},
                {"X-Forwarded-for", epp_util:readable_ip(PeerIp)}],