Remove leftover test code.

binder/config2.py

@@ -1,12 +0,0 @@
-c.ServerProxy.servers = {
-    'lab-dev': {
-        'command': [
-            'python',
-            '-m',
-            'http.server',
-            '{port}',
-        ]
-    }
-}
-
-c.NotebookApp.default_url = '/lab-dev'