Build fails because of new protobuf error MessageNotInitialized

[wscott]

Build currently fails.

$ cargo build
   Compiling ipfs v0.0.1 (file:///home/wscott/Documents/rust/rust-ipfs)
error[E0004]: non-exhaustive patterns: `MessageNotInitialized { .. }` not covered
   --> src/crypto/public_key.rs:171:15
    |
171 |         match err {
    |               ^^^ pattern `MessageNotInitialized { .. }` not covered

error: aborting due to previous error

error: Could not compile `ipfs`.

To learn more, run the command again with --verbose.

It appears protobuf added a new failure type.