csd_bs_list_to_bearer_cap(): add default branch for safety

Otherwise we may fail to initialize cap->data.{user,interm}_rate.

Change-Id: Ibfb71d1ece502585b55db0f28069a6aa0666b9df
Related: OS#6110, OS#4394
diff --git a/src/libmsc/csd_bs.c b/src/libmsc/csd_bs.c
index dcc6124..3a2c82a 100644
--- a/src/libmsc/csd_bs.c
+++ b/src/libmsc/csd_bs.c
@@ -467,6 +467,11 @@
 			cap->data.user_rate = GSM48_BCAP_UR_9600;
 			cap->data.interm_rate = GSM48_BCAP_IR_16k;
 			break;
+		default:
+			LOGP(DMSC, LOGL_ERROR,
+			     "%s(): bs=%d (rate=%u) is not implemented\n",
+			     __func__, bs, bs_map[bs].rate);
+			continue;
 		}
 
 		/* FIXME: handle more than one list entry */