Settings loader fix for not set range check entries

If we have a range or length check and the value is not set, skip, and do not convert either
Not set is None

src/corelibs/config_handling/settings_loader.py

@@ -331,6 +331,9 @@ class SettingsLoader:
         (__from, __to, __equal) = check
         valid = True
         for value_raw in convert_to_list(values):
+            # skip no tset values for range check
+            if not value_raw:
+                continue
             value = 0
             error_mark = ''
             if check_type == 'length':