Remove oslo.i18n entry from config-generator

oslo.i18n is not used in Tempest at all and it has been removed
from requirements.txt since Iff37af95269c38e4d435a53a21e5d60e2c5a3fa8
It is not necessary to keep it in config-generator, and this patch
removes it.

Related-Bug: #1620861
Change-Id: Icf43d6421f3a30ca72fdc4e985e070ebeb736fbb
1 file changed