[2672] Fix duplicate use of message ID

This is not allowed by our coding style. Use the correct message ID
instead (which was previously unused).

src/bin/stats/stats_httpd.py.in

@@ -413,7 +413,7 @@ class StatsHttpd:
         try:
             self.open_httpd()
         except HttpServerError as err:
-            logger.error(STATSHTTPD_SERVER_ERROR, err)
+            logger.error(STATSHTTPD_SERVER_INIT_ERROR, err)
             # restore old config
             self.load_config(old_config)
             self.open_httpd()