config_dump: bump protobuf/PGV versions to fix round-trip proto conversion bugs. (#3697)

* Bump protobuf dependency post 3.6.0 to 6a4fec616ec4b20f54d5fb530808b855cb664390. This
  brings in the following fixes:
  - https://github.com/google/protobuf/pull/4813 (fix bug when Any is directly embedded in a map)
  - https://github.com/google/protobuf/pull/4812 (preserve snake/camel-case across Any)
  - https://github.com/google/protobuf/pull/4811 (provide meaningful errors messages for missing fields)

* Bump PGV dependency to 345b6b478ef955ad31382955d21fb504e95f38c7. This bumps the Protobuf Go
  dependency to 1.0, necessary for the above protobuf dependency bump.

Risk level: Low
Testing: Added proto conversion and validation to integration_admin_test.

Signed-off-by: Harvey Tuch <htuch@google.com>

Mirrored from https://github.com/envoyproxy/envoy @ 9bb7df6bffbf9863939a3798299892a74c16c438

bazel/repositories.bzl

@@ -3,7 +3,7 @@ GOGOPROTO_SHA = "1adfc126b41513cc696b209667c8656ea7aac67c" # v1.0.0
 PROMETHEUS_SHA = "99fa1f4be8e564e8a6b613da7fa6f46c9edafc6c" # Nov 17, 2017
 OPENCENSUS_SHA = "ab82e5fdec8267dc2a726544b10af97675970847" # May 23, 2018
 
-PGV_GIT_SHA = "9f600c2cd2d7031fdc8e25e1c9f5ad81c8cab4fe"
+PGV_GIT_SHA = "345b6b478ef955ad31382955d21fb504e95f38c7"
 
 load("@bazel_tools//tools/build_defs/repo:git.bzl", "git_repository")