fdo#63154 Remove unused solar.h reference in sw.

Change-Id: I6e13f3705cb591573693cf60220e32aa823c5886
Reviewed-on: https://gerrit.libreoffice.org/8067
Tested-by: LibreOffice gerrit bot <gerrit@libreoffice.org>
Reviewed-by: Marcos Souza <marcos.souza.org@gmail.com>