Revert "Dev: tomcat: avoid unnecessary su when root"

This reverts commit fa27110abde3b17c09e155cbed2f9433a4e63e2b.

We found that skipping the su here may cause an unexpected timing issue
in opening catalina.out by catalina.sh which causes rotatelogs to fail.

The timing issue may potentially exist in the current code, but
it has been proven to work for years at least.