Merge pull request #4185 from HJianBo/upgrade_cowboy

chore(deps): upgrade cowboy to 2.8.2

rebar.config

@@ -42,7 +42,7 @@
 {deps,
     [ {gproc, {git, "https://github.com/uwiger/gproc", {tag, "0.8.0"}}}
     , {jiffy, {git, "https://github.com/emqx/jiffy", {tag, "1.0.5"}}}
-    , {cowboy, {git, "https://github.com/emqx/cowboy", {tag, "2.7.1"}}}
+    , {cowboy, {git, "https://github.com/emqx/cowboy", {tag, "2.8.2"}}}
     , {esockd, {git, "https://github.com/emqx/esockd", {tag, "5.8.0"}}}
     , {ekka, {git, "https://github.com/emqx/ekka", {tag, "0.8.0"}}}
     , {gen_rpc, {git, "https://github.com/emqx/gen_rpc", {tag, "2.5.0"}}}