Add sms_db param to config_values.py

Upcoming commit to rccn relies on this variable being defined

modules/rhizo_base/templates/config_values.py.erb

@@ -11,6 +11,7 @@ JB_out = '<%= @jb_out %>'
 
 rhizomatica_dir = '<%= @rhizomatica_dir %>'
 sq_hlr_path = '<%= @hlr_db %>'
+sms_db = '<%= @sms_db %>'
 bts_defs = '<%= @rhizomatica_dir %>/bts_defs.json'
 use_sip = '<%= @use_sip %>'
 advice_email = <%= @advice_email %>