umbim: add missing json_close_object call

Otherwise, connection setup may fail due to JSON parse error in netifd.

Signed-off-by: Martin Schiller <[email protected]>
[Updated commit description]
Signed-off-by: Lech Perczak <[email protected]>

package/network/utils/umbim/files/lib/netifd/proto/mbim.sh

@@ -154,6 +154,7 @@ _proto_mbim_setup() {
 	json_add_string proto "dhcpv6"
 	json_add_string extendprefix 1
 	proto_add_dynamic_defaults
+	json_close_object
 	ubus call network add_dynamic "$(json_dump)"
 }