fix #3356: NB fails to build
fix #3356: NB fails to build

Huertix/cgeo,S-Bartfast/cgeo,cgeo/cgeo,marco-dev/c-geo-opensource,kumy/cgeo,auricgoldfinger/cgeo,xiaoyanit/cgeo,cgeo/cgeo,tobiasge/cgeo,lewurm/cgeo,tobiasge/cgeo,tobiasge/cgeo,Bananeweizen/cgeo,schwabe/cgeo,brok85/cgeo,ThibaultR/cgeo,superspindel/cgeo,madankb/cgeo,rsudev/c-geo-opensource,lewurm/cgeo,yummy222/cgeo,brok85/cgeo,Huertix/cgeo,schwabe/cgeo,samueltardieu/cgeo,ThibaultR/cgeo,superspindel/cgeo,Bananeweizen/cgeo,vishwakulkarni/cgeo,vishwakulkarni/cgeo,schwabe/cgeo,rsudev/c-geo-opensource,cgeo/cgeo,madankb/cgeo,xiaoyanit/cgeo,matej116/cgeo,marco-dev/c-geo-opensource,S-Bartfast/cgeo,Bananeweizen/cgeo,samueltardieu/cgeo,xiaoyanit/cgeo,matej116/cgeo,KublaikhanGeek/cgeo,SammysHP/cgeo,pstorch/cgeo,mucek4/cgeo,rsudev/c-geo-opensource,matej116/cgeo,brok85/cgeo,yummy222/cgeo,SammysHP/cgeo,lewurm/cgeo,yummy222/cgeo,KublaikhanGeek/cgeo,S-Bartfast/cgeo,vishwakulkarni/cgeo,ThibaultR/cgeo,SammysHP/cgeo,pstorch/cgeo,pstorch/cgeo,cgeo/cgeo,marco-dev/c-geo-opensource,samueltardieu/cgeo,KublaikhanGeek/cgeo,kumy/cgeo,schwabe/cgeo,auricgoldfinger/cgeo,mucek4/cgeo,kumy/cgeo,Huertix/cgeo,auricgoldfinger/cgeo,mucek4/cgeo,superspindel/cgeo,madankb/cgeo