debian/rules: Don't overwrite .tarball-version

The .tarball-version file should contain the *source version* uniquely
identifying the git commit, and not the Debian package name.

With https://gerrit.osmocom.org/#/c/osmo-ci/+/10343/ there is a correct
.tarball-version file in the .tar.xz of the nightly source packages.

Change-Id: I4ce87d474687b61bc2104a02015e954425736123
Related: OS#3449
diff --git a/debian/rules b/debian/rules
index 10ba659..f59ca1e 100755
--- a/debian/rules
+++ b/debian/rules
@@ -14,13 +14,9 @@
 override_dh_strip:
 	dh_strip --dbg-package=libosmo-abis-dbg
 
-override_dh_autoreconf:
-	echo $(VERSION) > .tarball-version
-	dh_autoreconf
-
 override_dh_clean:
 	dh_clean
-	rm -f tests/package.m4 tests/testsuite .version .tarball-version
+	rm -f tests/package.m4 tests/testsuite .version
 
 override_dh_auto_test:
 	dh_auto_test || (find . -name testsuite.log -exec cat {} \; ; false)