clock: Fix content update if transform/autorotate
clock: Fix content update if transform/autorotate

fixes lxde/lxqt#883
Thanks to @jrvanwhy

DrTobe/lxqt-panel,cferr/lxqt-panel,stefonarch/lxqt-panel,lxde/lxqt-panel,rbazaud/lxqt-panel,Ilya87/lxqt-panel,stefonarch/lxqt-panel,DrTobe/lxqt-panel,ThomasVie/lxqt-panel-de,stefonarch/lxqt-panel,ThomasVie/lxqt-panel-de,cferr/lxqt-panel,lxde/lxqt-panel,Ilya87/lxqt-panel,pmattern/lxqt-panel,pmattern/lxqt-panel,rbazaud/lxqt-panel