gbproxy: Kill the global gbprox_global_patch_state struct

Move this patching state into the gbproxy_config as well.

Done by Jacob
diff --git a/openbsc/src/gprs/gb_proxy_vty.c b/openbsc/src/gprs/gb_proxy_vty.c
index 2b126f2..68d5e74 100644
--- a/openbsc/src/gprs/gb_proxy_vty.c
+++ b/openbsc/src/gprs/gb_proxy_vty.c
@@ -193,7 +193,7 @@
 		talloc_free(g_cfg->core_apn);
 		g_cfg->core_apn = NULL;
 		g_cfg->core_apn_size = 0;
-		gbprox_set_patch_filter(NULL, NULL);
+		gbprox_set_patch_filter(g_cfg, NULL, NULL);
 		return CMD_SUCCESS;
 	}
 
@@ -206,8 +206,8 @@
 	}
 
 	if (!filter) {
-		gbprox_set_patch_filter(NULL, NULL);
-	} else if (gbprox_set_patch_filter(filter, &err_msg) != 0) {
+		gbprox_set_patch_filter(g_cfg, NULL, NULL);
+	} else if (gbprox_set_patch_filter(g_cfg, filter, &err_msg) != 0) {
 		vty_out(vty, "Match expression invalid: %s%s",
 			err_msg, VTY_NEWLINE);
 		return CMD_WARNING;