delete folder cause stack overflow

[darkdh]

version: master 9566bcd

STR:

1. Make sure you have clean session
2. new folder “123” under toolbar
3. new folder “456” under “123”
4. delete folder “123"

there will be a infinite recursive call in removeSite due to parentFolderId is its folderId

[bsclifton]

this shouldn't be present in 0.12.8, since the about:newtab commits were not included

Root cause was found by @darkdh to be here:
dbe041d#diff-23ca389e2bcb77191b5a9c10900eb3a3R462

Fix in progress...