Added `BUILD_UNTIL_SUCCESS_SOURCE_FILES` keyword as a comment.
Added `BUILD_UNTIL_SUCCESS_SOURCE_FILES` keyword as a comment.

`build_until_success` will add the source files it finds below
`BUILD_UNTIL_SUCCESS_SOURCE_FILES`.

	modified:   external/gdal-2.1.1/CMakeLists.txt

nrz/ylikuutio,nrz/ylikuutio,nrz/ylikuutio,nrz/ylikuutio