reply sometimes showing [object Object] instead of recipients

[tomholub]

tested on 8.3.2, firefox. Seems we have some unsafe/unwanted conversions to string.

[rrrooommmaaa]

This appears to be solved by PR #4284.
This is how the reply is rendered after sending now (related test: user2@standardsubdomainfes.test:8001 - PWD encrypted message with FES - Reply rendering).