Fix kde4-l10n packages after sysutils/filelight's update

I chose filelight-17.* as it contains its own localization,
which is good, as kde4-l10n is very outdated, and may not
match modern filelight anymore.

Unfortunately this lead to conflicts with the kde4-l10n.

So strip the filelight parts from kde4-l10n-*.

Reported by: VVD (via IRC)
Reviewed by: rakuco
Pointyhat to: tcberner
Differential Revision: https://reviews.freebsd.org/D12393