Merge #12051: add missing debian contrib file to tarball

5d7ce74 add missing debian contrib files to tarball (Peter Wagner)

Pull request description:

  the current release is missing the debian contrib folder, add it

ACKs for commit 5d7ce7:

Tree-SHA512: 9d38c9ec0cc13171582c0bde57a2f69b22026a91f353e20da556cb63a4cfbba68b2465c9c62eaa98df50a65d971cc4411ffee519824b34068772ae8ddedb7d4c

Makefile.am

@@ -43,6 +43,7 @@ DIST_DOCS = $(wildcard doc/*.md) $(wildcard doc/release-notes/*.md)
 DIST_CONTRIB = $(top_srcdir)/contrib/bitcoin-cli.bash-completion \
 	       $(top_srcdir)/contrib/bitcoin-tx.bash-completion \
 	       $(top_srcdir)/contrib/bitcoind.bash-completion \
+	       $(top_srcdir)/contrib/debian/copyright \
 	       $(top_srcdir)/contrib/init \
 	       $(top_srcdir)/contrib/install_db4.sh
 DIST_SHARE = \