Exlude build of externals if already built.
Exlude build of externals if already built.

meshell/Cpp_project_template,mariokonrad/Cpp_project_template,meshell/Cpp_project_template,meshell/Cpp_project_template,mariokonrad/Cpp_project_template,meshell/Cpp_project_template,mariokonrad/Cpp_project_template