I only used the WoWSLauncher.cfg file from the folder rebuilt by dstud208. Changed "<item>http://update.worldofwarships.com</item>" to "<item>http://update.worldofwarships.eu</item>" and the client is updating now. ;-)
WoWSLauncher.cfg file looks like this:
...
<stats_service_url>http://wgusst-na.wargaming.net</stats_service_url>
<patch_info_urls>
<item>http://update.worldofwarships.eu</item>
<item>http://update-v4r4h10x.worldofwarships.com</item>
</patch_info_urls>
...