This is actually a pretty important fix. eglChooseConfig() might be the
first thing that fails when porobing for desktop GL / ES2 / ES3 support,
because EGL_RENDERABLE_TYPE is set values specific to the underlying
APIs.
Not sure how the hell this worked before. EGL 1.4 implementations
certainly could fail the call with EGL_BAD_ATTRIBUTE if
EGL_RENDERABLE_TYPE has EGL_OPENGL_ES3_BIT set. It's quite possible that
many EGL implementations tolerate invalid EGLConfig values steming from
uininitialized EGLConfig values (and eglCreateWindowSurface() even is
specified to return EGL_BAD_CONFIG error code for "not valid"
EGLConfigs).