Fix Compute name is lost at save

Fix #562

gns3server/controller/__init__.py

@@ -60,6 +60,7 @@ class Controller:
         Save the controller configuration on disk
         """
         data = {"computes": [{"host": c.host,
+                              "name": c.name,
                               "port": c.port,
                               "protocol": c.protocol,
                               "user": c.user,

gns3server/controller/compute.py

@@ -123,6 +123,7 @@ class Compute:
             self._session.close()
         self._connected = False
         self._controller.notification.emit("compute.updated", self.__json__())
+        self._controller.save()
 
     @asyncio.coroutine
     def close(self):