Fix 0011293: history_default_visible not per-project in bug_view_inc.php

bug_view_inc.php sets the project override ($g_project_override) after
getting the configuration option history_default_visible. Thus the
configuration option history_default_visible will be retrieved using the
wrong project (the one which is currently selected by the user cookie,
rather than the project of the bug the user is viewing).

Thanks to Chris Fitch for detecting this problem.