pylint: Fix use-dict-literal

Pylint 2.10 introduced new checker:
> Emitted when using dict() to create an empty dictionary instead of the
  literal {}. The literal is faster as it avoids an additional function
  call.

See pylint-dev/pylint#4365

Fixes: #279
Signed-off-by: Stanislav Levin <slev@altlinux.org>

tests/directorymock.py

@@ -125,4 +125,4 @@ def get_profiles(self):
 
     def get_profile(self, cn):
         logging.debug("Directory Mock: Getting profile %s", cn)
-        return self.data.profiles.get(cn, dict())
+        return self.data.profiles.get(cn, {})