lib/nova: Remove 'DEFAULT/verbose'

The 'verbose' option has been deprecated by oslo_log. Using it
results in a warning for the 'nova-manage' command and likely
many other OpenStack commands.

Change-Id: Icc11b25f56ebc62443c6afa90b9572d5c63b3882
Partial-bug: #1511505
diff --git a/lib/nova b/lib/nova
index 6c41403..47c43bd 100644
--- a/lib/nova
+++ b/lib/nova
@@ -480,7 +480,6 @@
 
     # (Re)create ``nova.conf``
     rm -f $NOVA_CONF
-    iniset $NOVA_CONF DEFAULT verbose "True"
     iniset $NOVA_CONF DEFAULT debug "$ENABLE_DEBUG_LOG_LEVEL"
     if [ "$NOVA_ALLOW_MOVE_TO_SAME_HOST" == "True" ]; then
         iniset $NOVA_CONF DEFAULT allow_resize_to_same_host "True"