Disable snapper init for IE <= 9

Snapper doesn't work at all for IE8 and IE9 and messes up with the main
container layout when enabled.

This commits disables snapper for these browsers.

Fixes https://github.com/owncloud/core/issues/8944

Please review @MorrisJobke @owncloud/designers 

@icewind1991 did you check snapper on your tablet ?