Only treat missing crate lists as empty
Only treat missing crate lists as empty

The motivation is that errors other than "file not found" could lead to
the file being overwritten by an empty config, e.g. if the `open` call
is interrupted and returns `EINTR`, then this code would read an empty
config and write it back later on. This can probably happen for other
errors as well (`ENFILE`, ...).

nipunn1313/cargo,tshepang/cargo,tsurai/cargo,AndiDog/cargo,achanda/cargo,sbeckeriv/cargo,tshepang/cargo,tshepang/cargo,blaenk/cargo,gchp/cargo,vojtechkral/cargo,nipunn1313/cargo,mark-buer/cargo,ThinTim/cargo,durka/cargo,tshepang/cargo,tsurai/cargo,rustyhorde/cargo,tsurai/cargo,mark-buer/cargo,sbeckeriv/cargo,brson/cargo,AndiDog/cargo,brson/cargo,AndiDog/cargo,ThinTim/cargo,ThinTim/cargo,nipunn1313/cargo,achanda/cargo,sbeckeriv/cargo,blaenk/cargo,rustyhorde/cargo,ThinTim/cargo,mark-buer/cargo,eminence/cargo,eminence/cargo,brson/cargo,eminence/cargo,vojtechkral/cargo,blaenk/cargo,sbeckeriv/cargo,gchp/cargo,vojtechkral/cargo,gchp/cargo,rust-lang/cargo,tsurai/cargo,rustyhorde/cargo,rust-lang/cargo,durka/cargo,durka/cargo,AndiDog/cargo,achanda/cargo,vojtechkral/cargo,gchp/cargo,nipunn1313/cargo,achanda/cargo,blaenk/cargo,durka/cargo,mark-buer/cargo,mark-buer/cargo,brson/cargo,rust-lang/cargo,rust-lang/cargo,blaenk/cargo,gchp/cargo,eminence/cargo,tsurai/cargo,rustyhorde/cargo,ThinTim/cargo,AndiDog/cargo,brson/cargo