Update Dockerfile

[DemanNL]

Fixes cp: can't stat '/app/ghostwriter/reporting/templates/reports/template.docx': No such file or directory

Identify the Bug

This pull requests fixes the following issue: https://github.com/GhostManager/Ghostwriter/issues/347

Description of the Change

The FAQ describes how to use chown django:django to resolve the issue. However the FAQ doesn't make persistent changes and as such following the FAQ doesn't really help (https://www.ghostwriter.wiki/getting-help/faq#stuck-waiting-for-django-to-start-502-bad-gateway)

Changing the dockerfile to include django:django did however solve the issue.

Verification Process

Did ghostwriter-cli install and now Django works.

Release Notes

• Fixed cp: can't stat '/app/ghostwriter/reporting/templates/reports/template.docx': No such file or directory error