Remove warning noise in ProjectImportOptions
Remove warning noise in ProjectImportOptions

Squlches these warnings:

```
/opt/gitlab/embedded/service/gitlab-rails/app/workers/concerns/project_import_options.rb:5: warning: already initialized constant ProjectImportOptions::IMPORT_RETRY_COUNT
/opt/gitlab/embedded/service/gitlab-rails/app/workers/concerns/project_import_options.rb:5: warning: previous definition of IMPORT_RETRY_COUNT was here
```

stoplightio/gitlabhq,dreampet/gitlab,mmkassem/gitlabhq,dreampet/gitlab,stoplightio/gitlabhq,jirutka/gitlabhq,jirutka/gitlabhq,mmkassem/gitlabhq,dreampet/gitlab,iiet/iiet-git,mmkassem/gitlabhq,axilleas/gitlabhq,stoplightio/gitlabhq,stoplightio/gitlabhq,axilleas/gitlabhq,iiet/iiet-git,mmkassem/gitlabhq,axilleas/gitlabhq,jirutka/gitlabhq,iiet/iiet-git,axilleas/gitlabhq,jirutka/gitlabhq,iiet/iiet-git,dreampet/gitlab