debian: remove unused variable from rules file
debian: don't run "make test" during package creation

The "make test" run failed while package creation  because the rtrlib
shared library couldn't be found.
I suppose it's because of the required -DCMAKE_SKIP_RPATH=True cmake
option in the debian rules file.
For now it's sufficient if the test are run manually and not
automatically when a debian package is created.
debian: change my debian maintainer mail address to git@...

I used a different mail addresses for the debian changelog entries and
the debian/control maintainer entry. This caused
changelog-should-mention-nmu lintian warnings.
debian: release debian package 0.2.3-1