faster startup

[carueda]

On the COR instance I noted a rather long delay for the orr service to completely be up and running:

$ docker logs -f orr
...
WARNING .. org.apache.catalina.util.SessionIdGeneratorBase.createSecureRandom 
Creation of SecureRandom instance for session ID generation using [SHA1PRNG] took [144,668] milliseconds.
...

https://wiki.apache.org/tomcat/HowTo/FasterStartUp#Entropy_Source suggests:

There is a way to configure JRE to use a non-blocking entropy source by setting the following system property: -Djava.security.egd=file:/dev/./urandom

which is mentioned in docker-library/tomcat#12