Remove useless error-checking code for non-valid use of `set_prolog_flag/2` as an entity directive
Remove useless error-checking code for non-valid use of `set_prolog_flag/2` as an entity directive

LogtalkDotOrg/logtalk3,LogtalkDotOrg/logtalk3,LogtalkDotOrg/logtalk3,LogtalkDotOrg/logtalk3,LogtalkDotOrg/logtalk3,LogtalkDotOrg/logtalk3,LogtalkDotOrg/logtalk3