Examples: Fix OpenGL3 example Makefile
Examples: Fix OpenGL3 example Makefile

gyakoo/imgui,burningreggae/imgui,nmlgc/imgui,dougbinks/imgui,andresv/imgui,thennequin/imgui,rxantos/imgui,wangshijin/imgui,usagi/imguixx,ggtucker/imgui,DXsmiley/FlexGUI,mikesart/imgui,neshume/imgui,Extrawurst/imgui,nmlgc/imgui,bagobor/imgui,cmaughan/imgui,twigletguy/imgui,nProtect/imgui,andresv/imgui,seanmiddleditch/imgui,kylawl/imgui,tom-seddon/imgui,nProtect/imgui,ghassanpl/imgui,burningreggae/imgui,ocornut/imgui,luiseduardohdbackup/imgui,wasikuss/imgui,sakishum/imgui,emoon/imgui,rmoorman/imgui,xunmengfeng/imgui,GHF/imgui,dougbinks/imgui,ocornut/imgui,benoitjacquier/imgui,wflohry/imgui-addons,bkaradzic/imgui,bkaradzic/imgui,xythobuz/imgui,ggtucker/imgui,cmaughan/imgui,Psybrus/imgui,bkaradzic/imgui,Flix01/imgui,redblobgames/imgui,redblobgames/imgui,rmoorman/imgui,shaggytwodope/imgui,Flix01/imgui,neshume/imgui,sakishum/imgui,rxantos/imgui,bagobor/imgui,zho7611/imgui,wasikuss/imgui,mikesart/imgui,elect86/imgui,thevaber/imgui,tpoechtrager/imgui,ocornut/imgui,Flix01/imgui,cmaughan/imgui,xythobuz/imgui,ggtucker/imgui,elect86/imgui,xunmengfeng/imgui,seanmiddleditch/imgui,thennequin/imgui,kylawl/imgui,wangshijin/imgui,aimotive/imgui-glfw,aimotive/imgui-glfw,gyakoo/imgui,ghassanpl/imgui,twigletguy/imgui,benoitjacquier/imgui,luiseduardohdbackup/imgui,usagi/imguixx,Extrawurst/imgui,thevaber/imgui,Psybrus/imgui,emoon/imgui,wflohry/imgui-addons,GHF/imgui,tpoechtrager/imgui,gamedeff/imgui,Pagghiu/imgui,DXsmiley/FlexGUI,tom-seddon/imgui,Pagghiu/imgui,zho7611/imgui,nProtect/imgui,gamedeff/imgui,cmaughan/imgui,shaggytwodope/imgui