Images in test steps attachments are not exported to Excel

Short description: Images in test step attachments are not exported to Excel

Steps to reproduce:

1. Create a template that iterates over test steps attachments in excel. (you can use this template Livro1 (3).xlsx)
2. Go to an issue of type test and add images in the test step attachment
3. Export the template of step 1

Actual Result: the images are not being exported. Instead of the images appears the URL

Expected Result: it should appear the image instead of the URL

Note: in word, this doesn't happen