message: Fixed .gitmodules
diff: [submodule "External/SPIRV-Tools"]
  path = External/SPIRV-Tools
  url = https://github.com/DiligentGraphics/SPIRV-Tools.git
  -[submodule "external/SPIRV-Headers"]
  +[submodule "External/SPIRV-Headers"]
  path = External/SPIRV-Headers
  url = https://github.com/DiligentGraphics/SPIRV-Headers.git
  