fdo#63154 Removed unused solar.h reference

Change-Id: I6b2f9e04e2232570c8bb9f36252b23a70c5f7525
Reviewed-on: https://gerrit.libreoffice.org/7604
Reviewed-by: Miklos Vajna <vmiklos@collabora.co.uk>
Tested-by: Miklos Vajna <vmiklos@collabora.co.uk>