Merge pull request #3874 from DarthGandalf/znc

znc: Support arm, upgrade alpine to 3.7

library/znc

@@ -1,6 +1,7 @@
 Maintainers: Alexey Sokolov <[email protected]> (@DarthGandalf)
 GitRepo: https://github.com/znc/znc-docker.git
-GitCommit: 642a0520caaf080f665c77c6abd8bc72d8223db6
+GitCommit: 7f4f14214b67e540892a281d69f855aefcef35ce
+Architectures: amd64, arm32v6
 
 Tags: 1.6.5, 1.6, latest
 Directory: full