dns/knot2: Update to 2.6.5

Additional port changes:

• Changed to DISTVERSION
• Replaced the second MASTER_SITES
• Added dependency to LIB_DEPENDS
• Removed USES=autoreconf
• Added USES=ncurses
• Removed extra patches

PR: 225957
Submitted by: Leo Vandewoestijne <freebsd@dns-lab.com> (mantainer)
Approved by: tcberner (mentor, implicit)