springboot Set includeantruntime in Ant smoke tests

Hi,

this PR is an attempt to get rid of a warning inside spring-boot-smoke-test-ant:

compile:
    [javac] /path/to/spring-boot-smoke-test-ant/build.xml:32: warning: 'includeantruntime' was not set, defaulting to build.sysclasspath=last; set to false for repeatable builds

Cheers, Christoph

Comment From: snicoll

That makes sense and removed the warning for me too. I am not sure what you meant by "an attempt to get rid of a warning" though.

Thanks again!

Comment From: dreis2211

I'm writing defensively. I've seen the "works on my machine" too often and then it doesn't work on the actual build machine. In this case probably not needed, though. Will be more clear in the future.