configitems: register the 'web.descend' config

mercurial/configitems.py

@@ -612,6 +612,9 b" coreconfigitem('web', 'csp',"
 coreconfigitem('web', 'deny_read',
     default=list,
 )
+coreconfigitem('web', 'descend',
+    default=True,
+)
 coreconfigitem('worker', 'backgroundclose',
     default=dynamicdefault,
 )

mercurial/hgweb/hgwebdir_mod.py

@@ -324,7 +324,7 b' class hgwebdir(object):'
 
         def rawentries(subdir="", **map):
 
-            descend = self.ui.configbool('web', 'descend', True)
+            descend = self.ui.configbool('web', 'descend')
             collapse = self.ui.configbool('web', 'collapse')
             seenrepos = set()
             seendirs = set()