library compilation error: #4

gcc5 - (ubuntu wiley)

When building the libraries (all of them)

Building libmuleappcore.a
ar: u' modifier ignored since D' is the default (see `U')

see http://gnu-automake.7480.n7.nabble.com/bug-20082-new-warning-from-ar-on-rawhide-systems-td21769.html

The apparent fix is to move ARFLAGS from cru to cr