gbproxy: Remove patch_mode, update initial checks

This patch removes the patch_mode feature including the related VTY
command patch-mode. Where sensible, the other configuration flags are
queried instead.

In addition, this initial checks in gbprox_process_bssgp_dl() and
gbprox_process_bssgp_ul() have been updated.

The patch mode feature has not been used and was increasingly
difficult to maintain.

Sponsored-by: On-Waves ehf
diff --git a/openbsc/src/gprs/gb_proxy.c b/openbsc/src/gprs/gb_proxy.c
index fbac298..f7afe94 100644
--- a/openbsc/src/gprs/gb_proxy.c
+++ b/openbsc/src/gprs/gb_proxy.c
@@ -283,7 +283,7 @@
 	int send_msg_directly = 0;
 
 	if (!cfg->core_mcc && !cfg->core_mnc && !cfg->core_apn &&
-	    !cfg->acquire_imsi)
+	    !cfg->acquire_imsi && !cfg->patch_ptmsi && !cfg->route_to_sgsn2)
 		return 1;
 
 	parse_ctx.to_bss = 0;
@@ -483,6 +483,10 @@
 	time_t now;
 	struct gbproxy_tlli_info *tlli_info = NULL;
 
+	if (!cfg->core_mcc && !cfg->core_mnc && !cfg->core_apn &&
+	    !cfg->acquire_imsi && !cfg->patch_ptmsi && !cfg->route_to_sgsn2)
+		return;
+
 	parse_ctx.to_bss = 1;
 
 	rc = gprs_gb_parse_bssgp(msgb_bssgph(msg), msgb_bssgp_len(msg),