debug: add PROXY category, move all proxy logs to it

lib/debug_config.c

@@ -126,6 +126,7 @@ static const struct {
     {"etcp_dump", DEBUG_CATEGORY_ETCP_DUMP},
     {"chat_sync", DEBUG_CATEGORY_CHAT_SYNC},
     {"member_sync", DEBUG_CATEGORY_MEMBER_SYNC},
+    {"proxy", DEBUG_CATEGORY_PROXY},
     {"all", DEBUG_CATEGORY_ALL},
     {NULL, DEBUG_CATEGORY_NONE}
 };