See merge request nexedi/slapos.package!169

 * use cp instead of mv so that the original file doesn't disappear and we
can rerun the script
 * osc rm can fail if the package is empty (especially at creation time
of the package)

Use § for sed separator instead of | so that we can have | in variables.

We need | in PACKAGE_BUILD_DEPENDENCIES of fluent-bit

dep--fluent-bit was just a development package with less dependencies

OBS_PROJECT will be by default the branch project of our production
project : home:VIFIBnexedi:branches:home:VIFIBnexedi

Then if everything compile fine on the branch project, we will submit
the package on OBS website.

See https://www.debian.org/doc/manuals/maint-guide/dother.en.html#dirs

See merge request nexedi/slapos.package!164

lunzip is used as a basic example.

See merge request nexedi/slapos.package!168

we use https only starting from debian 11

with backported fixes for debian 11 compatibility

fixup for 203927d9

The old dsc was not removed correctly

See merge request !166