webgui: add missing dictionary for THistDrawable classes
webgui: add missing dictionary for THistDrawable classes

Required for correct I/O of histograms drawables
olifre/root,karies/root,karies/root,karies/root,karies/root,karies/root,root-mirror/root,karies/root,root-mirror/root,olifre/root,olifre/root,root-mirror/root,olifre/root,root-mirror/root,karies/root,root-mirror/root,olifre/root,karies/root,olifre/root,root-mirror/root,olifre/root,root-mirror/root,karies/root,olifre/root,karies/root,root-mirror/root,olifre/root,root-mirror/root,olifre/root,root-mirror/root,root-mirror/root,olifre/root,karies/root