fix DLGSUP logging cat after change in libosmocore

DLGSUP must no longer be added to applications' logging category arrays after
change-id Id974c7be158e4d60421a98110f5c807aefd31119 in libosmocore.

Todo: once above change is merged to libosmocore, bump the required libosmocore
version in configure.ac.

Change-Id: I74ab1a031d1ed144468b016294d2965eba5e7d1d
diff --git a/src/logging.c b/src/logging.c
index 54c8900..9b8de45 100644
--- a/src/logging.c
+++ b/src/logging.c
@@ -13,12 +13,6 @@
 		.color = "\033[1;31m",
 		.enabled = 1, .loglevel = LOGL_DEBUG,
 	},
-	[DLGSUP] = {
-		.name = "DLGSUP",
-		.description = "GSUP Protocol",
-		.color = "\033[1;32m",
-		.enabled = 1, .loglevel = LOGL_INFO,
-	},
 	[DAUC] = {
 		.name = "DAUC",
 		.description = "Authentication Center",