Fix empty override settings

Apparently empty dropdowns now return None

modules/infotext_utils.py

@@ -421,6 +421,9 @@ def create_override_settings_dict(text_pairs):
 
     res = {}
     
+    if not text_pairs:
+        return res
+
     params = {}
     for pair in text_pairs:
         k, v = pair.split(":", maxsplit=1)