Update DEVSTACK_SERIES to wallaby

stable/victoria branch has been created now and
current master is for wallaby.

Change-Id: I5f5b233127d6ef24452fcd05db990f9ddc244dc4
diff --git a/stackrc b/stackrc
index bf1ad3d..a36f897 100644
--- a/stackrc
+++ b/stackrc
@@ -245,7 +245,7 @@
 # Setting the variable to 'ALL' will activate the download for all
 # libraries.
 
-DEVSTACK_SERIES="victoria"
+DEVSTACK_SERIES="wallaby"
 
 ##############
 #