not idempotent if plugin modifies key/values

[markus2330]

When I write non-utf8 to toml plugin, long sequences of characters are generated (probably doubled every time Ansible gets executed). E.g. Kü����������������������������������������che.

There are at least two problems:

1. Ansible should preferable write its own config, not what it got from the host

2. Ansible does not show the warning:

 2: Module toml issued the warning C03200:
        Validation Semantic: Key 'user:/sw/libelektra/.../#0/current/.../loc' contained non-UTF-8 value. Invalid byte sequences will be replaced with replacement character U+FFFD. Mark the key as binary and use base64 plugin to preserve non-UTF-8 values