Use ldflags instead of ldlibs, because wx-config --libs mixes libs and ldflags, and...

Use ldflags instead of ldlibs, because wx-config --libs mixes libs and ldflags, and being able to specify order of ldflags is important. (e.g. on Leopard, if any other *-config script adds -L/usr/lib to the linker flags, wx will link against the system-provided wx.) (2.9 port)

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@49816 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775