[0.17.x] Desync during rendering of [special-item=] tag on linux

[cogito123]

Hi,

The desync is 100% reproducible on my machine. When I enter in multiplayer chat:

[special-item=0eNp1jtEKwjAMRX9l5rnCxkShvyIi3YxboU1Lm4lj9N9N54sv5iFwL/eeZIPBLRiTJQa9gR0DZdDXDbKdyLjq8RoRNFhGDwrI+Ko4GcoxJD4O6BiKAksPfIPuyk0BElu2+CXtYr3T4gdMEvjHUBBDllqgelVQrYJVdqnE/br+eVaBM1ITb0bnQvNMwTc8YzPOhiZ0YTpI5oUp78BL33YnmbY/l/IBb4pSQQ==]

Server then says that I desynced and I re download map.

I don't even have to send it, the moment I type last ']' character, the icon is rendered with the text and then it instantly desynced.
https://www.sendspace.com/file/03gmgv

My spec:
os: Ubuntu 18.04.1 LTS
rest info I saw in desync report

[Rseding91]

Thanks for the report. It's now fixed for the next version of 0.17.