egl/haiku: drop overwritten preset of EGL version

egl/haiku: drop overwritten preset of EGL version

`init_haiku()` is called by `eglInitialize()`, which then calls
`_eglComputeVersion()` (without even anything in between). The latter
sets the EGL version based on the extensions supported, and since Haiku
doesn't support any it will end up overwriting the same `1.4` value.

Signed-off-by: Eric Engestrom <eric@engestrom.ch>
Reviewed-by: Frank Binns <frank.binns@imgtec.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6131>