The specified clients in this commit used to rely on wlr_egl and
some of its related functions in order to render surfaces.
This is no longer the case as of this commit.
Client examples using wlr_egl would fail with EGL_BAD_CONFIG because they
need an EGL config. Set the config attribs to a non-NULL value to make
sure wlr_egl creates an EGL config.
Fixes: 037710b1d4 ("render/egl: support config-less wlr_egl")
Simon Ser
Brandon Dowdy