fix install-crashpad so it can install pre-built macOS binaries
fix install-crashpad so it can install pre-built macOS binaries

- e.g. via `sudo ./install-crashpad osx`

JanMarvin/rstudio,JanMarvin/rstudio,JanMarvin/rstudio,JanMarvin/rstudio,JanMarvin/rstudio,JanMarvin/rstudio,JanMarvin/rstudio,JanMarvin/rstudio,JanMarvin/rstudio