inst.reason isn't alway in the form (errno, strerror)
urllib2.urlopen("foobar://foo") is an example
where inst.reason is a string
fix issue383
#header#
<title>Mercurial repositories index</title>
</head>
<body>
<h2>Mercurial Repositories</h2>
The specified repository "#repo|escape#" is unknown, sorry.
Please go back to the main repository list page.
#footer#