credits: add back "developers not committing code since 2010-09-28"

done so by bringing back the relevant part that was removed in
https://bitbucket.org/spaetz/gitanaly/commits/9854ae0b40d5f8c2ab4d0dcb59b2c4639cd179fb

Change-Id: I31c1e918854c0e8a3bd354b41c8a1cbf2a5af003
Reviewed-on: https://gerrit.libreoffice.org/4474Reviewed-by: Fridrich Strba <fridrich@documentfoundation.org>
Tested-by: Fridrich Strba <fridrich@documentfoundation.org>