Correction restitution URL source

src/Main.php

@@ -705,7 +705,7 @@ EOF
 
                     case '':
                         if (preg_match('`^Original\s+source\s*:\s*.+href\s*=\s*"(?<url>[^"]+)"`i', $match['value'], $matchUrl) === 1) {
-                            $metadata->source = $matchUrl['url'];
+                            $metadata->url = $matchUrl['url'];
                         }
                         elseif (preg_match('`^Exported\s+with`i', $match['value']) !== 1) {
                             $metadata->summary = $match['value'];
@@ -954,4 +954,4 @@ EOF
         $metaColumn->setAttribute('name', 'calibre:user_metadata:#' . $name);
         $metaColumn->setAttribute('content', json_encode($content));
     }
-}
+}