helpers: fix metatags extraction in case description is empty

rhodecode/lib/helpers.py

@@ -986,10 +986,10 b' def extract_metatags(value):'
     """
     Extract supported meta-tags from given text value
     """
+    tags = []
     if not value:
-        return ''
+        return tags, ''
 
-    tags = []
     for key, val in tags_paterns.items():
         pat, replace_html = val
         tags.extend([(key, x.group()) for x in pat.finditer(value)])

rhodecode/tests/lib/test_libs.py

@@ -187,6 +187,14 b' def test_age_in_future(age_args, expecte'
 
 
 @pytest.mark.parametrize("sample, expected_tags", [
+    # entry
+    ((
+             ""
+     ),
+     [
+
+     ]),
+    # entry
     ((
         "hello world [stale]"
      ),