Merge branch 'lintian-fixes' into 'master'

Fix some issues reported by lintian

See merge request !16

debian/control

@@ -2,7 +2,7 @@ Source: acmeserver
 Section: admin
 Priority: optional
 Maintainer: Autistici/Inventati <debian@autistici.org>
-Build-Depends: debhelper-compat (= 12), golang-any (>= 1.11), dh-golang
+Build-Depends: debhelper-compat (= 13), golang-any (>= 1.11), dh-golang
 Standards-Version: 3.9.6
 
 Package: acmeserver