sysutils/backuppc4: Update to 4.1.5

Update WWW [1].

Changes: https://github.com/backuppc/backuppc/releases/tag/4.1.5

PR: 224109 [1]
PR: 224076
Reported by: Zane C. Bowers-Hadley <vvelox@vvelox.net> [1]
Submitted by: Alexander Moisseev <moiseev@mezonplus.ru> (maintainer)