Multirow compatibility for Zen Browser

[Harut12345]

Hello,

I’m using Zen-Mod-Forbidden-Horizontal-Tabs: https://github.com/mmmintdesign/Zen-Mod-Forbidden-Horizontal-Tabs

The problem is that I can’t get it to work with multirow in TabMixPlus because I get the message "These preferences are not in use for vertical tabs." It would be great to find a solution to enable multirow.

Thanks in advance.

[onemen]

see #371