fixed url scheme check

Author: oscarotero

src/Http/Url.php

@@ -654,7 +654,7 @@ function ($matches) {
             throw new \InvalidArgumentException('Malformed URL: ' . $url);
         }
 
-        if (empty($parts['scheme']) || !in_array($parts['scheme'], ['http', 'https'])) {
+        if (!empty($parts['scheme']) && !in_array($parts['scheme'], ['http', 'https'])) {
             throw new \InvalidArgumentException(sprintf('Invalid URL scheme: "%s"', $parts['scheme']));
         }