IuPS: GMM Attach: reset MM ctx pending_req

Change-Id: I0df0f3d88085939eb617405e2013ad164eed477b
diff --git a/openbsc/src/gprs/gprs_gmm.c b/openbsc/src/gprs/gprs_gmm.c
index 99e4a8c..c17d813 100644
--- a/openbsc/src/gprs/gprs_gmm.c
+++ b/openbsc/src/gprs/gprs_gmm.c
@@ -836,6 +836,7 @@
 			  "no pending request, authorization completed\n");
 		break;
 	case GSM48_MT_GMM_ATTACH_REQ:
+		ctx->pending_req = 0;
 
 		extract_subscr_msisdn(ctx);
 		extract_subscr_hlr(ctx);