REGRESSION (r158036): WebView cannot handle HTTP Basic Authentication challenge
https://bugs.webkit.org/show_bug.cgi?id=138843
rdar://problem/18793695

Reviewed by Dan Bernstein.

* Panels/WebAuthenticationPanel.m:
(-[WebAuthenticationPanel cancel:]):
(-[WebAuthenticationPanel logIn:]):
Don't close the panel before using panel.sheetParent, because the parent becomes nil.
In fact, we don't need to close it at all, it's enough to call orderOut:, and even
that only when using an old NSWindow API.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@177011 268f45cc-cd09-0410-ab3c-d52691b4dbfc