Fix when config file doesn't have computes section (#1062)

gns3server/controller/__init__.py

@@ -82,7 +82,7 @@ class Controller:
                                                              password=server_config.get("password", ""),
                                                              force=True)
         except aiohttp.web_exceptions.HTTPConflict as e:
-            log.fatal("Can't acces to the local server, make sure anything else is not running on the same port")
+            log.fatal("Can't access to the local server, make sure anything else is not running on the same port")
             sys.exit(1)
         for c in computes:
             try:
@@ -176,7 +176,7 @@ class Controller:
         if "gns3vm" in data:
             self.gns3vm.settings = data["gns3vm"]
 
-        return data["computes"]
+        return data.get("computes", [])
 
     @asyncio.coroutine
     def load_projects(self):