commit 8424236daafac98d560f4408318efd6e62872840
set the entry to a specific size to prevent it from
growing for long passwords.
The size is a little too long though, since it makes
the dialog pop out horizontally when showing the entry.
This commit drops it down a few em.
https://bugzilla.gnome.org/show_bug.cgi?id=659370
fb81efeecf
