Examples: SDL+OpenGL3: fixed build on ES2 target. (#4492)
Examples: SDL+OpenGL3: fixed build on ES2 target. (#4492)

bkaradzic/imgui,ocornut/imgui,bkaradzic/imgui,bkaradzic/imgui,ggtucker/imgui,Flix01/imgui,Flix01/imgui,Flix01/imgui,ocornut/imgui,nProtect/imgui,nProtect/imgui,ocornut/imgui,ggtucker/imgui,ggtucker/imgui,nProtect/imgui