Fix release script

Author: reda-alaoui

release.sh

@@ -1,7 +1,4 @@
 #!/usr/bin/env bash
-env | grep MAVEN_GPG_PASSPHRASE > /dev/null
-if [ $? -eq 1 ]; then
- echo "Environment variable 'MAVEN_GPG_PASSPHRASE' is missing. Set it to empty if there is no passphrase."
- exit 1
-fi
+# Prime gpg-agent caches. See https://maven.apache.org/plugins/maven-gpg-plugin/usage.html
+echo "test" | gpg --clearsign > /dev/null
 ./mvnw --batch-mode clean release:prepare release:perform && git push && git push --tags