Plotter: fix for older GCC.
Plotter: fix for older GCC.

tschmidt23/Pangolin,wxdzju/Pangolin,mp3guy/Pangolin,mp3guy/Pangolin,wxdzju/Pangolin,randi120/Pangolin,mp3guy/Pangolin,tschmidt23/Pangolin,stevenlovegrove/Pangolin,renzodenardi/Pangolin,randi120/Pangolin,stevenlovegrove/Pangolin,stevenlovegrove/Pangolin,renzodenardi/Pangolin,tschmidt23/Pangolin