Undefined function mime_content_type()

Not seeing images in articles. Seeing this error in log:
E_ERROR (1) classes/handler/public.php:1061 Call to undefined function mime_content_type()

If possible include steps to reproduce the problem:
Opening an article with an image

tt-rss version (including git commit id):
17.4

Platform (i.e. Linux distro, PHP, PostgreSQL, etc) versions:
Shared hosting

Please provide any additional information below:

You need to make sure the fileinfo PHP module is installed and enabled.

Fantastic. Thanks for the quick reply - solved

this should probably be added to sanity checks