Update ansifilter to version 2.20 / rev 15 via SR 1093599
https://build.opensuse.org/request/show/1093599
by user 1Antoine1 + dimstar_suse
- Update to version 2.20:
* Fixed invalid array access (gl#saalen/ansifilter#35).
* CLI: Added `--no-default-fg` option to omit default foreground
color (gl#saalen/ansifilter#37).