Fix conflicts

rebar.config

@@ -3,7 +3,7 @@
      {cowboy, "2.6.1"}, % hex
      {gproc, "0.8.0"}, % hex
      {esockd, "5.5.0"}, %hex
-     {ekka, {git, "https://github.com/emqx/ekka", {tag, "v0.5.8"}}},
+     {ekka, "0.6.0"}, %hex
      {gen_rpc, {git, "https://github.com/emqx/gen_rpc", {tag, "2.4.1"}}},
      {cuttlefish, {git, "https://github.com/emqx/cuttlefish", {tag, "v3.0.0"}}}
     ]}.