osmo-mgw: Config file is osmo-mgw.cfg, and not mgcp.cfg

Change-Id: I16016684ee5bd6d82a8867d4b2be108b6d718291
diff --git a/src/osmo-mgw/mgw_main.c b/src/osmo-mgw/mgw_main.c
index e21baa8..99efb15 100644
--- a/src/osmo-mgw/mgw_main.c
+++ b/src/osmo-mgw/mgw_main.c
@@ -73,7 +73,7 @@
 	"This is free software: you are free to change and redistribute it.\r\n"
 	"There is NO WARRANTY, to the extent permitted by law.\r\n";
 
-static char *config_file = "mgcp.cfg";
+static char *config_file = "osmo-mgw.cfg";
 
 /* used by msgb and mgcp */
 void *tall_bsc_ctx = NULL;