Skip gpg-connect-agent when cleaning up temporary GPG home directories

It appears this is sometimes done when it wasn't needed, causing
gpg-connect-agent to wait for an agent to start so that it can tell it
to stop, which results in a lot of noise on stderr when running `flatpak
update`. Debian 10 has GPG 2.2, and according to the commit message of
the commit I'm reverting here, this cleanup should be unnecessary with
GPG >= 2.2.

debian/patches/series

@@ -1 +1,2 @@
 debian/Skip-test-pull-repeated-during-CI.patch
+debian/Revert-lib-Kill-GPG-agent-when-cleaning-up-tmp-homedirs.patch