dispatch: don't clamp the range of the exit code twice
We already limit the range to (0, 255) in the call to sys.exit(). The
duplicated operation can't possibly be hurting us, but let's clean it up
to avoid confusion.
#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