always return just "$CXX -o" from `wx-config --ld` instead of returning the

always return just "$CXX -o" from `wx-config --ld` instead of returning the
command needed to link a shared library (if this is really needed, we should
add another --shared-ld option for this) as it isn't suitable for linking the
user applications

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@49270 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775