fix #2144: webview on non UI thread exception
fix #2144: webview on non UI thread exception

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