Do not quote GPG command

Release making script fails on this line:
"$GPG" --passphrase "$GPG_PASSPHRASE" --export-secret-key --armor "$GPG_KEY" > "$GPG_KEY_FILE"
 

./dev-support/create-release/do-release-docker.sh: line 118: gpg --pinentry-mode loopback --no-tty --batch: command not found