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
diff --git a/tempest/cmd/config-generator.tempest.conf b/tempest/cmd/config-generator.tempest.conf
index d718f93..49ad62d 100644
--- a/tempest/cmd/config-generator.tempest.conf
+++ b/tempest/cmd/config-generator.tempest.conf
@@ -2,7 +2,6 @@
 output_file = etc/tempest.conf.sample
 namespace = tempest.config
 namespace = oslo.concurrency
-namespace = oslo.i18n
 namespace = oslo.log
 namespace = oslo.serialization
 namespace = oslo.utils