children: fix the log expansion of `hg children` in doc
`hg log -r children()` returns `hg: parse error: missing argument`.
Differential Revision: https://phab.mercurial-scm.org/D1269
--- a/hgext/children.py Sun Oct 29 17:53:52 2017 +0900
+++ b/hgext/children.py Tue Oct 31 06:39:38 2017 +0530
@@ -49,7 +49,7 @@
Please use :hg:`log` instead::
- hg children => hg log -r "children()"
+ hg children => hg log -r "children(.)"
hg children -r REV => hg log -r "children(REV)"
See :hg:`help log` and :hg:`help revsets.children`.