Fixes an exception in combination
with the yamlProvider as a target
The unmodified value object isn't
represented as string while
building the yaml output
The Exception:
yaml.representer.RepresenterError:
('cannot represent an object', 1.1.1.1)
yaml/representer.py@249,
represent_undefined()
TransIP allows '@' as value to alias the root record.
'@' was on populate appended with the zone, which trigger an unneeded update.
'@' => '@.example.com.' -> 'example.com'
This fix will stop the unneeded update
