Upgrade the esockd library to v5.4.2

Makefile

@@ -10,7 +10,7 @@ dep_jsx     = git https://github.com/talentdeficit/jsx 2.9.0
 dep_gproc   = git https://github.com/uwiger/gproc 0.8.0
 dep_gen_rpc = git https://github.com/emqx/gen_rpc 2.2.0
 dep_lager   = git https://github.com/erlang-lager/lager 3.6.5
-dep_esockd  = git https://github.com/emqx/esockd v5.4.1
+dep_esockd  = git https://github.com/emqx/esockd v5.4.2
 dep_ekka    = git https://github.com/emqx/ekka v0.4.1
 dep_cowboy  = git https://github.com/ninenines/cowboy 2.4.0
 dep_clique  = git https://github.com/emqx/clique develop