double quotes

src/freedombone-app-bdsmail

     systemctl start bdsmail
 
     echo '#!/bin/bash' > /usr/bin/bdsmail_domain
-    echo 'cd $BDSMAIL_DIR' >> /usr/bin/bdsmail_domain
+    echo "cd $BDSMAIL_DIR" >> /usr/bin/bdsmail_domain
     echo 'if [ ! -f bdsmail-privkey.dat ]; then' >> /usr/bin/bdsmail_domain
     echo '    exit 1' >> /usr/bin/bdsmail_domain
     echo 'fi' >> /usr/bin/bdsmail_domain