chore: update emqx_statsd.app.src descriptions

Co-authored-by: Zaiming (Stone) Shi <zmstone@gmail.com>

apps/emqx_statsd/src/emqx_statsd.app.src

@@ -1,6 +1,6 @@
 %% -*- mode: erlang -*-
 {application, emqx_statsd, [
-    {description, "EMQ X Statsd"},
+    {description, "EMQX Statsd"},
     {vsn, "5.0.3"},
     {registered, []},
     {mod, {emqx_statsd_app, []}},