Translate German variable names

Act -> Current

Not a translation per se, but correction of usage of "actual"
(German: "wirklich") instead of "current" (German: "aktuell").

This is similar to the Akt -> Current translation done on
commit b62ac98a in the same file.

Change-Id: I462106ee5d2b07b09bb567b962bcb97d76859d81
Reviewed-on: https://gerrit.libreoffice.org/58873Reviewed-by: Michael Stahl <Michael.Stahl@cib.de>
Tested-by: Michael Stahl <Michael.Stahl@cib.de>