pass -e flag to echo (to escape \n)

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@18296 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/CMFActivity/bin/watch_activities

 #!/bin/sh
 
 if [ $# -ne 1 ]; then
-  echo "Usage:\n  $0 <db_name>"
+  echo -e "Usage:\n  $0 <db_name>"
   exit 1
 fi