chgserver: add fastannotate config section to sensitive list
Depending on the config value of `fastannotate.modes`, the fastannotate
extension can do different things in uisetup. Depending on value of
`fastannotate.server`, it can register new wireprotocol capabilities.
This fixes test-fastannotate-hg.t, test-fastannotate-protocol.t and
test-fastannotate.t with chg.
{header}
<title>Mercurial Error</title>
</head>
<body>
<h2>Mercurial Error</h2>
<p>
An error occurred while processing your request:
</p>
<p>
{error|escape}
</p>
{footer}