Revert "key-manager: set the primary-toolbar style class on the toolbar"
Revert "key-manager: set the primary-toolbar style class on the toolbar"

This reverts commit 283ed05a53dc32892bc115b7d7e2c69d31f875c6.

This broke the display of the main seahorse window on GTK+ 2.x

See https://bugzilla.gnome.org/show_bug.cgi?id=644216

ueno/seahorse,ueno/seahorse