configure: remove C++ support
configure: remove C++ support

With the Android backend gone, there is no C++ code anymore. Remove
support for C++ in the build.

Signed-off-by: Pekka Paalanen <6c0263d81461c956d504307112a4ce25eaacc3d1@gmail.com>

Fantu/compositor-spice,sir-murray/weston,mchalupa/weston,mchalupa/weston,xorgy/weston,jonnylamb/weston,sir-murray/weston,udoprog/weston,Gnurou/weston,jonnylamb/weston,Gnurou/weston,Tarnyko/weston-xdg_surface_present,eyolfson/weston,udoprog/weston,krezovic/weston,Fantu/compositor-spice,xorgy/weston,kwm81/weston,Tarnyko/weston-xdg_surface_present,giucam/weston,Fantu/compositor-spice,krezovic/weston,eyolfson/weston,kwm81/weston,giucam/weston