Always check for null coordinates before saving them
Always check for null coordinates before saving them

Fixes #441.

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