If `/run/opengl-driver/lib` is in `LD_LIBRARY_PATH`, bwrap will try to
mount it into the already bind mounted `/run/opengl-driver`. To
prevent this, we instead specify the subpaths of `/run/opengl-driver`
we're interested in.
Also, use the correct path for i686 builds.
Without access to the `/run/opengl-driver` directory, webkit fails to
create an EGL context, since it can't identify a suitable EGL
vendor. This results in a blank window and the following error output:
Cannot get default EGL display: EGL_BAD_PARAMETER
Cannot create EGL context: invalid display (last error: EGL_SUCCESS)
