Fix an un-initialized data member . This fixes the seg-fault  observed in  https://root-forum.cern.ch/t/rooprodpdf-changes-behaviour-after-print-call/27202
Fix an un-initialized data member . This fixes the seg-fault  observed in  https://root-forum.cern.ch/t/rooprodpdf-changes-behaviour-after-print-call/27202

olifre/root,karies/root,root-mirror/root,root-mirror/root,karies/root,olifre/root,karies/root,root-mirror/root,root-mirror/root,root-mirror/root,olifre/root,root-mirror/root,olifre/root,karies/root,olifre/root,karies/root,olifre/root,karies/root,olifre/root,karies/root,karies/root,olifre/root,root-mirror/root,root-mirror/root,root-mirror/root,karies/root,root-mirror/root,karies/root,root-mirror/root,olifre/root,olifre/root,karies/root,olifre/root