Update field.html to add |safe template tag

[jplaverdure]

field.label was no longer marked as 'safe', preventing the use of html content in model's verbose_name definition

[smithdc1]

Thanks for the PR. However, this is a deliberate change to avoid content accidentally being marked as safe in a template and therefore avoid a potential security issue.

If you need to mark the label as safe this should be done in your project code.