Default mpirun behavior for Java apps incorrect if PRTE libdir != OMPI libdir

[jsquyres]

See openpmix/prrte#1335 for details. Filing this here just to track it on the OMPI side.

This is a regression compared to v4.x (because ORTE handled this in v4.x, but now this functionality is in PRTE, and therefore PRTE's libdir could be different than OMPI's libdir -- and therefore mpirun won't add the right libdir to the Java classpath).

[janjust]

@jsquyres Looks like fixed in @10246 with miscellaneous cleanups? If so, can we close?