use secure URL in -allow_unknown_hoster help

Author: stapelberg

make.go

@@ -695,7 +695,7 @@ func execMake(args []string) {
 	fs.BoolVar(&allowUnknownHoster,
 		"allow_unknown_hoster",
 		false,
-		"The pkg-go naming conventions (see http://pkg-go.alioth.debian.org/packaging.html) use a canonical identifier for the hostname, and the mapping is hardcoded into dh-make-golang. In case you want to package a Go package living on an unknown hoster, you may set this flag to true and double-check that the resulting package name is sane. Contact pkg-go if unsure.")
+		"The pkg-go naming conventions (see https://pkg-go.alioth.debian.org/packaging.html) use a canonical identifier for the hostname, and the mapping is hardcoded into dh-make-golang. In case you want to package a Go package living on an unknown hoster, you may set this flag to true and double-check that the resulting package name is sane. Contact pkg-go if unsure.")
 
 	var pkgType string
 	fs.StringVar(&pkgType,