Bug#808312: Fix overwrite chemps2.1.gz

[Sebastian Wouters]

Hi Andreas,

The bug is hopefully fixed with
https://anonscm.debian.org/cgit/debichem/packages/chemps2.git/commit/?id=c787f951661b39221db198de19577b88ac1629e1

I'll ask Graham or Michael to upload.

Best wishes,
Sebastian