xpra: 2.2.5 -> 2.2.6

Semi-automatic update generated by https://github.com/ryantm/nixpkgs-update tools.

This update was made based on information from https://repology.org/metapackage/xpra/versions.

These checks were done:

- built on NixOS
- ran ‘/nix/store/yh7iwzli0pcqnhm2vdcc2ha5ifig1ix0-xpra-2.2.6/bin/xpra -h’ got 0 exit code
- ran ‘/nix/store/yh7iwzli0pcqnhm2vdcc2ha5ifig1ix0-xpra-2.2.6/bin/xpra --help’ got 0 exit code
- ran ‘/nix/store/yh7iwzli0pcqnhm2vdcc2ha5ifig1ix0-xpra-2.2.6/bin/udev_product_version -h’ got 0 exit code
- ran ‘/nix/store/yh7iwzli0pcqnhm2vdcc2ha5ifig1ix0-xpra-2.2.6/bin/udev_product_version --help’ got 0 exit code
- ran ‘/nix/store/yh7iwzli0pcqnhm2vdcc2ha5ifig1ix0-xpra-2.2.6/bin/udev_product_version help’ got 0 exit code
- ran ‘/nix/store/yh7iwzli0pcqnhm2vdcc2ha5ifig1ix0-xpra-2.2.6/bin/.xpra_launcher-wrapped -h’ got 0 exit code
- ran ‘/nix/store/yh7iwzli0pcqnhm2vdcc2ha5ifig1ix0-xpra-2.2.6/bin/.xpra_launcher-wrapped --help’ got 0 exit code
- ran ‘/nix/store/yh7iwzli0pcqnhm2vdcc2ha5ifig1ix0-xpra-2.2.6/bin/xpra_launcher -h’ got 0 exit code
- ran ‘/nix/store/yh7iwzli0pcqnhm2vdcc2ha5ifig1ix0-xpra-2.2.6/bin/xpra_launcher --help’ got 0 exit code
- ran ‘/nix/store/yh7iwzli0pcqnhm2vdcc2ha5ifig1ix0-xpra-2.2.6/bin/..xpra-wrapped-wrapped -h’ got 0 exit code
- ran ‘/nix/store/yh7iwzli0pcqnhm2vdcc2ha5ifig1ix0-xpra-2.2.6/bin/..xpra-wrapped-wrapped --help’ got 0 exit code
- ran ‘/nix/store/yh7iwzli0pcqnhm2vdcc2ha5ifig1ix0-xpra-2.2.6/bin/.xpra-wrapped -h’ got 0 exit code
- ran ‘/nix/store/yh7iwzli0pcqnhm2vdcc2ha5ifig1ix0-xpra-2.2.6/bin/.xpra-wrapped --help’ got 0 exit code
- found 2.2.6 with grep in /nix/store/yh7iwzli0pcqnhm2vdcc2ha5ifig1ix0-xpra-2.2.6
- directory tree listing: https://gist.github.com/01ffc3c415200e59fd7469357044a87a