Merge pull request #276 from Tim-Zhang/update-protobuf-to-fix-box_pointers

ttrpc-codegen: bump protobuf-codegen to 3.5.1

Author: Hui Zhu

ttrpc-codegen/Cargo.toml

@@ -17,5 +17,5 @@ readme = "README.md"
 home = "=0.5.9"
 protobuf-support = "3.2.0"
 protobuf = { version = "2.27.1" }
-protobuf-codegen = "3.2.0"
+protobuf-codegen = "3.5.1"
 ttrpc-compiler = "0.6.1"