Configuration: Sane empty result

The settings/base.py file is expeting a dictionary of configuration
options. If there is no config.yml, return and empty dictionary
instead of a None result.

Signed-off-by: Roberto Rosario <roberto.rosario.gonzalez@gmail.com>

mayan/settings/utils.py

@@ -36,7 +36,7 @@ def read_configuration_file(path):
                     )
     except IOError as exception:
         if exception.errno == errno.ENOENT:
-            pass
+            return {}
         else:
             raise