perf(http): bump ehttpc version

rebar.config

@@ -37,7 +37,7 @@
 
 {deps,
     [ {gpb, "4.11.2"} %% gpb only used to build, but not for release, pin it here to avoid fetching a wrong version due to rebar plugins scattered in all the deps
-    , {ehttpc, {git, "https://github.com/emqx/ehttpc", {tag, "0.1.12"}}}
+    , {ehttpc, {git, "https://github.com/emqx/ehttpc", {tag, "0.1.13"}}}
     , {eredis_cluster, {git, "https://github.com/emqx/eredis_cluster", {tag, "0.6.5"}}}
     , {gproc, {git, "https://github.com/uwiger/gproc", {tag, "0.8.0"}}}
     , {jiffy, {git, "https://github.com/emqx/jiffy", {tag, "1.0.5"}}}