Compile Horizon message catalogs during stack.sh

Recently compiled message catalogs (mo files) were removed
in Horizon and django_openstack_auth repositories.
We need to compile message catalogs to make translations
available for Horizon users. It is useful for developers too.

Change-Id: I0831e8308205c116d8e3bb8b43be7f0dd6fa0c0a
diff --git a/files/rpms/general b/files/rpms/general
index 7a35961..d4a9fcb 100644
--- a/files/rpms/general
+++ b/files/rpms/general
@@ -26,6 +26,7 @@
 which
 bc
 libyaml-devel
+gettext  # used for compiling message catalogs
 
 # [1] : some of installed tools have unversioned dependencies on this,
 # but others have versioned (<=0.7).  So if a later version (0.7.1)