Fix bad variable reference

1 job for add/build in 1 minute and 31 seconds (queued for 3 seconds)
Status Job ID Name Coverage
  Build
failed #4006
package

00:01:31

 
Name Stage Failure
failed
package Build
-rw-rw-rw-. 1 root root     0 May 28 01:02 .gitignore
-rw-rw-rw-. 1 root root 637 May 28 01:02 .gitlab-ci.yml
-rw-rw-rw-. 1 root root 18052 May 28 01:02 LICENSE
-rw-rw-rw-. 1 root root 312 May 28 01:02 README.md
-rw-r--r--. 1 root root 7886 May 28 01:02 nginx_1.17.0-1~eth-jessie.diff.gz
-rw-r--r--. 1 root root 3006 May 28 01:02 nginx_1.17.0-1~eth-jessie_amd64.build
-rw-r--r--. 1 root root 170 May 28 01:02 nginx_1.17.0-1~eth.orig.tar.gz
drwxrwxrwx. 4 root root 4096 May 28 01:02 source
ERROR: Job failed: exit code 1