Fix permission error in ZNC

https://github.com/znc/znc-docker/issues/1

Also switch to libressl, as I've realized that it's installed in alpine
by default

library/znc

@@ -2,9 +2,9 @@ Maintainers: Alexey Sokolov <[email protected]> (@DarthGandalf)
 GitRepo: https://github.com/znc/znc-docker.git
 
 Tags: 1.6.4, 1.6, latest
-GitCommit: 7bf73d259149c476f09d765a008973076d0e48cb
+GitCommit: be14d42ab7a49d36285fb1b3d0f12de422705617
 Directory: full
 
 Tags: 1.6.4-slim, 1.6-slim, slim
-GitCommit: 7bf73d259149c476f09d765a008973076d0e48cb
+GitCommit: be14d42ab7a49d36285fb1b3d0f12de422705617
 Directory: slim