GrabHandle: Use "pane-separator" class for proper theming
GrabHandle: Use "pane-separator" class for proper theming

Signed-off-by: Bertrand Lorentz <eb7ac131ef7bff6d2ebccd6e5bf9a7cb6485cf2c@gmail.com>

GNOME/hyena,arfbtwn/hyena,arfbtwn/hyena,GNOME/hyena