Enable clang's sign-conversion diagnostic since it does not warn on any code
Enable clang's sign-conversion diagnostic since it does not warn on any code

LebedevRI/rawspeed,darktable-org/rawspeed,LebedevRI/rawspeed,darktable-org/rawspeed,LebedevRI/rawspeed,darktable-org/rawspeed,darktable-org/rawspeed,darktable-org/rawspeed,LebedevRI/rawspeed,LebedevRI/rawspeed