mercurial/commands.py

--- a/mercurial/commands.py	Tue Mar 21 23:30:13 2017 +0100
+++ b/mercurial/commands.py	Tue Mar 21 21:26:52 2017 -0700
@@ -5349,7 +5349,7 @@
     if rev and node:
         raise error.Abort(_("please specify just one revision"))
 
-    if ui.configbool('commands', 'update.requiredest', False):
+    if ui.configbool('commands', 'update.requiredest'):
         if not node and not rev and not date:
             raise error.Abort(_('you must specify a destination'),
                               hint=_('for example: hg update ".::"'))