macsec: T2023: only remove interface when it exists
macsec: T2023: only remove interface when it exists

If for whatever reason the macsec interface dropped out of the Kernel - only
call .remove() when it still exists to avoid any exceptions at all.

vyos/vyos-1x,vyos/vyos-1x,vyos/vyos-1x,vyos/vyos-1x