You may try using the "--libraries" option during deploy or place the log4j.jar file with the Log4J settings file under lib directory of your war file.
--libraries
A comma-separated list of library JAR files. Specify the
library JAR files by their relative or absolute paths.
Specify relative paths relative to instance-
root/lib/applibs. The libraries are made available to
the application in the order specified.
Please feel free to add the information to the USER FAQ wiki when you get it to work.