HBASE-22852 Stop gpg agent daemons in hbase nightlies. (#525)

Signed-off-by: Stack <stack@apache.org>
Signed-off-by: Sean Busbey <busbey@apache.org>

dev-support/jenkins-scripts/cache-apache-project-artifact.sh

@@ -78,6 +78,12 @@ else
 fi
 
 function cleanup {
+  if [ -n "${keys}" ]; then
+    echo "Stopping gpg agent daemon"
+    gpgconf --homedir "${working_dir}/.gpg" --kill gpg-agent
+    echo "Stopped gpg agent daemon"
+  fi
+
   if [ "true" = "${cleanup}" ]; then
     echo "cleaning up temp space."
     rm -rf "${working_dir}"