python-optional-src: Removal of this python2 module

python-optional-src: Removal of this python2 module

- python-optional-src was not getting built anyway as it was not listed
   in make.sh
- lfs file was missing most of the standard content. No source info
   and no build instructions
- missing source file from IPFire source system
- grep on build/ found no dependencies on this module

Signed-off-by: Adolf Belka <adolf.belka@ipfire.org>
Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>