@ symbol in filtered resource prevents subsequent filters

This was something that broke for us upgrading from 2.3 to 2.4.2:

In a file containing:
sqlplus user/pass@$1 @${regression.oracle.scripts}/purge.sql
impdp user/pass@$1 PARFILE=${regression.oracle.scripts}/imp.par DIRECTORY=dump_dir DUMPFILE=${2}

The second occurrence of ${regression.oracle.scripts} wouldn't get substituted, I think due to the odd number of '@' characters.

Defining another property <oracle.at>@</oracle.at> worked around the issue for me:

sqlplus user/pass@$1 ${oracle.at}${regression.oracle.scripts}/purge.sql
impdp user/pass@$1 PARFILE=${regression.oracle.scripts}/imp.par DIRECTORY=dump_dir DUMPFILE=${2}