Ombi: Integrate with profiles, Retire user defaults

NOTE: If you previously used the Ombi integration, New ombi users
won't be created until you set this up.

Ombi settings can be added to a profile in Settings > User Profiles.
The "Modify settings" options will now apply to ombi if the selected
profile has ombi settings.

ombi/ombi.go

@@ -217,5 +217,6 @@ func (ombi *Ombi) NewUser(username, password, email string, template map[string]
 		}
 		return lst, code, err
 	}
+	ombi.cacheExpiry = time.Now()
 	return nil, code, err
 }