Update .version during execute_before_dh_auto_configure instead of patching it

We are facing again https://bugs.debian.org/1011531 since the patch was not updated. Instead of doing it manually, let's add some automation.

Patching the version means we have to update the patch for each new upstream release which is prone to errors. Instead we rely on standard Debian tools to update it at the beginning of the build process.

Signed-off-by: Dylan Aïssi dylan.aissi@collabora.com