Bump protobuf from 2.27.1 to 3.2.0 in /src/rust/engine#15

dependabot[bot] wants to merge 1 commit intomainepsagon/pants:mainfrom

dependabot/cargo/src/rust/engine/protobuf-3.2.0epsagon/pants:dependabot/cargo/src/rust/engine/protobuf-3.2.0Copy head branch name to clipboard