diff -r ab9121fda8d2 -r 90a1b62bdc91 mercurial/configitems.py
--- a/mercurial/configitems.py	Fri Jun 30 03:44:11 2017 +0200
+++ b/mercurial/configitems.py	Fri Jun 30 03:44:12 2017 +0200
@@ -131,6 +131,9 @@
 coreconfigitem('server', 'maxhttpheaderlen',
     default=1024,
 )
+coreconfigitem('server', 'preferuncompressed',
+    default=False,
+)
 coreconfigitem('ui', 'clonebundleprefers',
     default=list,
 )