Create non-existing path in setLocationAction()

When using qbittorrent-nox it is not always possible to manually create
the target path for torrent moving. This commit allows automatic path
creation. It also allows to display error messages in the
'Set location' window.

src/webui/www/private/scripts/mocha-init.js

@@ -417,7 +417,7 @@ initializeWindows = function() {
                 paddingVertical: 0,
                 paddingHorizontal: 0,
                 width: 400,
-                height: 100
+                height: 130
             });
         }
     };