databases/slony1v2: port cleanup

• Use OPTIONS helpers for the PERLTOOLS option
• Remove a redundant block of code for setting PGSQL_VER: this functionality is already supplied via 'USES+= pgsql'
• Maintainer's timeout (olgeni@FreeBSD.org)

PR: 185906
Submitted by: Matthew Seaman <matthew@FreeBSD.org>