Fixed #993: Bug - Inconsistent data in database for created_by field from customers

    [feedquote='i-MSCP Github (stable) (nuxwin)','https://github.com/i-MSCP/imscp/commit/76b490dbe78f6394cc4a0fe41d09fd4b6b32da57']

    Code
    1. Fixed #993: Bug - Inconsistent data in database for created_by field from customers
    2. Small fixes

    [/feedquote]