switch to use ceilometermiddleware

swift middleware contained in ceilometer is now deprecated. the
middleware is available in ceilometermiddleware.

Change-Id: I6e41986245f4d95a9385dc7829479ed1199f10ac
diff --git a/stack.sh b/stack.sh
index 2060f2d..5c726a3 100755
--- a/stack.sh
+++ b/stack.sh
@@ -739,6 +739,9 @@
 fi
 
 if is_service_enabled s-proxy; then
+    if is_service_enabled ceilometer; then
+        install_ceilometermiddleware
+    fi
     stack_install_service swift
     configure_swift