Merge pull request #532 from expsa/hr_custom

Update __init__.py

odex25_hr/months_custom/__init__.py

@@ -25,7 +25,7 @@ _logger = logging.getLogger(__name__)
 def format_date(env, value, lang_code=False, date_format=False):
     if not value:
         return ''
-    if isinstance(value, pycompat.string_types):
+    if isinstance(value, str):
         if len(value) < DATE_LENGTH:
             return ''
         if len(value) > DATE_LENGTH: