chore(deps): update version of hocon

rebar.config

@@ -61,7 +61,7 @@
     , {observer_cli, "1.7.1"} % NOTE: depends on recon 2.5.x
     , {getopt, "1.0.2"}
     , {snabbkaffe, {git, "https://github.com/kafka4beam/snabbkaffe.git", {tag, "0.14.1"}}}
-    , {hocon, {git, "https://github.com/emqx/hocon.git", {tag, "0.19.6"}}}
+    , {hocon, {git, "https://github.com/emqx/hocon.git", {tag, "0.20.3"}}}
     , {emqx_http_lib, {git, "https://github.com/emqx/emqx_http_lib.git", {tag, "0.4.1"}}}
     , {esasl, {git, "https://github.com/emqx/esasl", {tag, "0.2.0"}}}
     , {jose, {git, "https://github.com/potatosalad/erlang-jose", {tag, "1.11.1"}}}