Strip path from root

If there is a path (the URL path) specified under paths in the
configuration, which points to a root (a physical folder on the
filesystem), this path should not be attached to the root. This fix will
do that. It strips the path from the root.

Example configuration:

hosts:
  localhost:
    paths:
      -
        path: /a
        root: public/aroot
      -
        path: /
        root: public

Filesystem:
+ public
  + index.gmi
  + aroot
    + index.gmi

serve_https.go

@@ -80,7 +80,9 @@ func serveHTTPS(w http.ResponseWriter, r *http.Request) (int, int64, string) {
 						root += "/"
 					}
 
-					requestSplit := strings.Split(r.URL.Path, "/")
+					// We remove the the path (specified in the config file) from the actual URL, so
+					// it will not prefixed two times to the root.
+					requestSplit := strings.Split(r.URL.Path[len(serve.Path)-1:], "/")
 
 					if !serve.SymLinks {
 						for i := 1; i < len(requestSplit); i++ {