DockerFile for Mac users to run DeepfaceLab with CPU Mode (#95)

* fix localization nullpointer exception

* fix devicelib error line:61,remove e

* support create docker from cpu dockerfile

* support preview or not when train(resolve cannot connect to X server)

nnlib/devicelib.py

@@ -58,7 +58,7 @@ class devicelib:
         try:
             nvmlInit()
             nvmlShutdown()
-        except e:
+        except:
             return False
         return True