Fix Can't connect to compute local on some computers

Chicken and egg problem we try to connect to compute
before http was available. I rewrote the code to prevent
erase of settings and rollback the beta4 code for init.

Fix #946

gns3server/controller/__init__.py

@@ -248,7 +248,6 @@ class Controller:
         """
         Store settings shared by the different GUI will be replace by dedicated API later. Dictionnary
         """
-        assert self._settings is not None
         return self._settings
 
     @settings.setter