Friendlier error message when Tor is closed or network is down

Signed-off-by: Jesús <heckyel@hyperbola.info>

youtube/__init__.py

@@ -108,6 +108,12 @@ def error_page(e):
         if exc_info()[1].ip:
             error_message += '\n\nExit node IP address: ' + exc_info()[1].ip
         return flask.render_template('error.html', error_message=error_message, slim=slim), 502
+    elif exc_info()[0] == util.FetchError and exc_info()[1].error_message:
+        return (flask.render_template(
+                    'error.html',
+                    error_message=exc_info()[1].error_message,
+                    slim=slim
+                ), 502)
     return flask.render_template('error.html', traceback=traceback.format_exc(), slim=slim), 500