Merge pull request mozilla#1973 from tilmankamp/fix1972

Fix mozilla#1972

Author: tilmankamp

util/text.py

@@ -135,6 +135,7 @@ def validate_label(label):
     label = label.replace("?", "")
     label = label.replace("\"", "")
     label = label.strip()
+    label = label.lower()
 
-    return label.lower()
+    return label if label else None