share: remove unexpected heading from "verbose" container in help test
`test-gendoc-*.t` have been failing for me since 91425656e2b1 (share:
add documentation about share-safe mode in `hg help -e share`,
2020-11-27) with this kind of output:
```
--- /usr/local/google/home/martinvonz/hg/tests/test-gendoc-ru.t
+++ /usr/local/google/home/martinvonz/hg/tests/test-gendoc-ru.t.err
@@ -2,3 +2,9 @@
$ $TESTDIR/check-gendoc ru
checking for parse errors
+ gendoc.txt:12818: (SEVERE/4) Unexpected section title.
+
+ Sharing requirements and configs of source repository with shares
+ -----------------------------------------------------------------
+ Exiting due to level-4 (SEVERE) system message.
+ [1]
```
This patch fixes that.
Differential Revision: https://phab.mercurial-scm.org/D9552
syntax: glob
*.elc
*.tmp
*.orig
*.rej
*~
*.mergebackup
*.o
*.so
*.dll
*.exe
*.pyd
*.pyc
*.pyo
*$py.class
*.swp
*.prof
*.zip
\#*\#
.\#*
tests/artifacts/cache/big-file-churn.hg
tests/.coverage*
tests/.testtimes*
tests/.hypothesis
tests/hypothesis-generated
tests/annotated
tests/exceptions
tests/*.err
tests/htmlcov
build
contrib/chg/chg
contrib/hgsh/hgsh
contrib/vagrant/.vagrant
dist
packages
doc/common.txt
doc/*.[0-9]
doc/*.[0-9].txt
doc/*.[0-9].gendoc.txt
doc/*.[0-9].{x,ht}ml
MANIFEST
MANIFEST.in
patches
mercurial/__modulepolicy__.py
mercurial/__version__.py
mercurial/hgpythonlib.h
mercurial.egg-info
.DS_Store
tags
cscope.*
.vscode/*
.idea/*
.asv/*
.pytype/*
.mypy_cache
i18n/hg.pot
locale/*/LC_MESSAGES/hg.mo
hgext/__index__.py
rust/target/
rust/*/target/
# Generated wheels
wheelhouse/
syntax: regexp
^\.pc/
^\.(pydev)?project
# hackable windows distribution additions
^hg-python
^hg.py$