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!!)