Fixed data seperation bug.
Fixed data seperation bug.

A PLOT_GROUP column with only NA values was interpreted as group values,
but without proper data handling downstream. This is now handled
correctly.

thehyve/heim-Rmodules,UMich-Transmart/Rmodules,baumjamin/Rmodules,cdejonge/Rmodules,baumjamin/Rmodules,thehyve/heim-Rmodules,cdejonge/Rmodules,UMich-Transmart/Rmodules,thehyve/Rmodules,thehyve/Rmodules_oncoprint,UMich-Neptune-Transmart/Rmodules,baumjamin/Rmodules,cdejonge/Rmodules,thehyve/Rmodules,wimvanderlinden/Rmodules,thehyve/Rmodules_oncoprint,UMich-Neptune-Transmart/Rmodules,transmart/Rmodules,thehyve/heim-Rmodules,thehyve/heim-Rmodules,UMich-Neptune-Transmart/Rmodules,baumjamin/Rmodules,UMich-Transmart/Rmodules,cdejonge/Rmodules,UMich-Neptune-Transmart/Rmodules,thehyve/Rmodules,wimvanderlinden/Rmodules,wimvanderlinden/Rmodules,transmart/Rmodules,wimvanderlinden/Rmodules,thehyve/Rmodules_oncoprint,transmart/Rmodules,thehyve/Rmodules,UMich-Transmart/Rmodules,transmart/Rmodules