configitems: enable pullbundles by default
The use of pullbundles is already protected: they are only used
when a pullbundles.manifest file is created on the server.
Having an additional flag doesn't really make sense
and can confuse users (as indicated in the mercurial mailing list
on the topic "Can't get pull-bundles working").
#if no-windows no-osx
$ mkdir -p xdgconf/hg
$ echo '[ui]' > xdgconf/hg/hgrc
$ echo 'username = foobar' >> xdgconf/hg/hgrc
$ XDG_CONFIG_HOME="`pwd`/xdgconf" ; export XDG_CONFIG_HOME
$ unset HGRCPATH
$ hg config ui.username 2>/dev/null
foobar
#endif