GitHub: fix announcement

GitHub/config.py

@@ -69,7 +69,7 @@ conf.registerGlobalValue(GitHub, 'announces',
         registry.String('', _("""You shouldn't edit this configuration
         variable yourself, unless you know what you do. Use '@Github announce
         add' or '@Github announce remove' instead.""")))
-conf.registerGlobalValue(GitHub, 'tiny',
+conf.registerChannelValue(GitHub, 'tiny',
         registry.String('http://tinyurl.com/api-create.php', _("""The URL
         used to tinyfy the commit link (must be compatible with TinyURL.com
         """)))

GitHub/plugin.py

@@ -139,7 +139,7 @@ class GitHub(callbacks.Plugin):
             bold = ircutils.bold
             url = commit['url']
             data = urllib.urlencode({'url': url})
-            tiny = self.registryValue('tiny', channel)
+            tiny = instance.registryValue('tiny', channel)
             url = urllib.urlopen(tiny, data).read()
             s = '%s/%s (in %s): %s committed %s %s' % \
                     (payload['repository']['owner']['name'],