Fix typo in ServerLoggingConfig

This caused us not to interpolate the server name into the default
log path.

Change-Id: I6ec5c2a425e0d538c902fddf3fdfb12a79f18dac
diff --git a/zuul/ansible/logconfig.py b/zuul/ansible/logconfig.py
index 86bcd47..ef1621f 100644
--- a/zuul/ansible/logconfig.py
+++ b/zuul/ansible/logconfig.py
@@ -208,7 +208,7 @@
             server_handler = handler.copy()
             server_handler['filename'] = server_handler['filename'].format(
                 server=server)
-            self._config['handlers'][name] = handler
+            self._config['handlers'][name] = server_handler
         # Change everything configured to write to stdout to write to
         # log files instead. This leaves root going to console, which is
         # how the loggers infra uses work.