[Bug-gnuzilla] mailto links can't be handler. icecat 17.01

[Nikita Zlobin]

I have icecat 17.0.1 from ppa on launchpad.net. When i click on mailto
link, nothing happens, though i have to copy link and paste in where it
should appear. I compared with what is available in firefox. Firefox
has application handler for mailto, which for me is set to claws-mail.
Icecat doesn't have it. However, it is not settings. I compared
settings on about:config page, filtered by 'mailto' word, and three
mailto handlers are found in both. But in firefox they are set to
Yandex, Mail.Ru and yet another webmail apps. In icecat they all are
"chrome://browser-region/locale/region.properties". Other settings are
same.