chore: update grpc-erl to 0.6.8

mix.exs

@@ -57,7 +57,7 @@ defmodule EMQXUmbrella.MixProject do
       {:rocksdb, github: "emqx/erlang-rocksdb", tag: "1.7.2-emqx-11", override: true},
       {:ekka, github: "emqx/ekka", tag: "0.15.2", override: true},
       {:gen_rpc, github: "emqx/gen_rpc", tag: "2.8.1", override: true},
-      {:grpc, github: "emqx/grpc-erl", tag: "0.6.7", override: true},
+      {:grpc, github: "emqx/grpc-erl", tag: "0.6.8", override: true},
       {:minirest, github: "emqx/minirest", tag: "1.3.10", override: true},
       {:ecpool, github: "emqx/ecpool", tag: "0.5.3", override: true},
       {:replayq, github: "emqx/replayq", tag: "0.3.7", override: true},

rebar.config

@@ -64,7 +64,7 @@
     , {rocksdb, {git, "https://github.com/emqx/erlang-rocksdb", {tag, "1.7.2-emqx-11"}}}
     , {ekka, {git, "https://github.com/emqx/ekka", {tag, "0.15.2"}}}
     , {gen_rpc, {git, "https://github.com/emqx/gen_rpc", {tag, "2.8.1"}}}
-    , {grpc, {git, "https://github.com/emqx/grpc-erl", {tag, "0.6.7"}}}
+    , {grpc, {git, "https://github.com/emqx/grpc-erl", {tag, "0.6.8"}}}
     , {minirest, {git, "https://github.com/emqx/minirest", {tag, "1.3.10"}}}
     , {ecpool, {git, "https://github.com/emqx/ecpool", {tag, "0.5.3"}}}
     , {replayq, {git, "https://github.com/emqx/replayq.git", {tag, "0.3.7"}}}