Adding new join game failed message if two players with the same ip address want to join a ranking game.

src/net/socket_msg.h

@@ -117,6 +117,7 @@
 #define NTF_NET_JOIN_GAME_NAME_IN_USE	216
 #define NTF_NET_JOIN_GAME_BAD_NAME		217
 #define NTF_NET_JOIN_INVALID_SETTINGS	218
+#define NTF_NET_JOIN_IP_BLOCKED			219
 
 // Notifications - version
 #define NTF_NET_NEW_RELEASE_AVAILABLE	220