Bug 6235 : Corrects the behaviour of the humanmsg box on IE8 and IE7.

Bug 6235 : Corrects the behaviour of the humanmsg box on IE8 and IE7.

Without this fix, the black box that appears when you save system
preferences doesn't disappear on IE.

Fix from http://code.google.com/p/humanmsg/issues/detail?id=1
(Thanks Owen Leonard)

Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Paul Poulain <paul.poulain@biblibre.com>
Signed-off-by: Chris Cormack <chrisc@catalyst.net.nz>
(cherry picked from commit 661bcfadbdca6d6d6c1cdb8ba9c398e6c0b45b8f)

Signed-off-by: Chris Nighswonger <chris.nighswonger@gmail.com>