Revert "Do not rely on the url scheme owncloud(s) any more."

This reverts commit 34dd3b207e.
It can be implemented simpler.

csync/src/csync_owncloud.c

@@ -486,8 +486,9 @@ static int dav_connect(const char *base_url) {
         strcpy( protocol, "https");
         useSSL = 1;
     } else {
-        // Trust the original protocol
-        strcpy( protocol, scheme );
+        DEBUG_WEBDAV("Invalid scheme %s, go outa here!", scheme );
+        rc = -1;
+        goto out;
     }
 
     DEBUG_WEBDAV("* user %s", dav_session.user ? dav_session.user : "");