Revert "Update conf.py"

This reverts commit 239b364a.

docs/source/conf.py

@@ -21,7 +21,7 @@ class Mock(MagicMock):
     def __getattr__(cls, name):
         return MagicMock()
 
-MOCK_MODULES = ['PyTango', 'tango']
+MOCK_MODULES = ['PyTango']
 sys.modules.update((mod_name, Mock()) for mod_name in MOCK_MODULES)
 
 # If extensions (or modules to document with autodoc) are in another directory,