Ticket 47340 - Deleting a separator ',' in 7-bit check plugin arguments makes the
                   server fail to start with segfault
    
    Bug Description:  If invalid or missing plugin arguments are present in the config entry,
                      the server will crash at startup.  This is because we were not fully
                      validating all argument values.
    
    Fix Description:  Generate an appropriate error at startup when invalid settings are
                      detected, and gracefully exit.
    
    https://fedorahosted.org/389/ticket/47340
    
    Reviewed by: Noriko(Thanks!!)