Plugin OpenDKIM: Hide experimental smartmatch usage warnings

    [feedquote='i-MSCP Github (plugins) (nuxwin)','https://github.com/i-MSCP/plugins/commit/b2f1f562915231384038610f542ccb04c80e5669']

    Code
    1. Plugin OpenDKIM: Hide experimental smartmatch usage warnings
    2. Plugin Postscreen: Hide experimental smartmatch usage warnings
    3. Plugin RoundcubePlugins: Hide experimental smartmatch usage warnings +typo
    4. Plugin SpamAssassin: Hide experimental smartmatch usage warnings

    [/feedquote]