libmobile: add missing method to header and add missing semi colon

libmobile.h

@@ -48,5 +48,6 @@ struct json_object *mobile_get_sim_state(struct dongle *dev);
 struct json_object *mobile_activate_sim(struct dongle *dev, char *pin);
 struct json_object *mobile_get_remaining_tries_puk(struct dongle *dev);
 struct json_object *mobile_get_traffic_statistics(struct dongle *dev);
-void set_lib_debug(int debug_level)
+struct json_object *mobile_get_system_info(struct dongle *dev);
+void set_lib_debug(int debug_level);
 #endif