use f-strings in module utils (#10901)

* use f-strings in module utils

* Apply suggestions from code review

Co-authored-by: Felix Fontein <felix@fontein.de>

* remove unused imports

---------

Co-authored-by: Felix Fontein <felix@fontein.de>

plugins/module_utils/mh/base.py

@@ -40,7 +40,7 @@ class ModuleHelperBase(object):
     def __getattr__(self, attr):
         if attr in self._delegated_to_module:
             return getattr(self.module, attr)
-        raise AttributeError("ModuleHelperBase has no attribute '%s'" % (attr, ))
+        raise AttributeError(f"ModuleHelperBase has no attribute '{attr}'")
 
     def __init_module__(self):
         pass