PluginDownloader: Update URL of my repo

I also kept the old one as nyuszika7h-old for now, as I don't have an
ETA on updating those plugins.

plugins/PluginDownloader/plugin.py

@@ -273,6 +273,10 @@ repositories = {
                                                    'Supybot-plugins'
                                                    ),
                'nyuszika7h':       GithubRepository(
+                                                   'nyuszika7h',
+                                                   'limnoria-plugins'
+                                                   ),
+               'nyuszika7h-old':   GithubRepository(
                                                    'nyuszika7h',
                                                    'Supybot-plugins'
                                                    ),