Resolves: fdo#62682 crash on second export of svg

because the first export has left "dangling" CalcFieldValueHdl Links in
Outliners that got created based on the Drawing Outliner while it had a
temporary CalcFieldValueHdl installed, and didn't get the old CalcFieldValueHdl
installed when the old Drawing Outliner one was re-installed.

Change-Id: I064a154ece488c9a4c3467b753451df7e73ae883