Upgrade metrics-graphite to 4.1.6

This aligns with the version used in core Gerrit's stable-3.2 and
master branches.

Bug: Issue 12671
Change-Id: I680f5a3f5790d15c5d6891dd5a0c8cbbc8e7a976
diff --git a/external_plugin_deps.bzl b/external_plugin_deps.bzl
index 5c6a513..91f67b2 100644
--- a/external_plugin_deps.bzl
+++ b/external_plugin_deps.bzl
@@ -3,6 +3,6 @@
 def external_plugin_deps():
     maven_jar(
         name = "metrics_graphite",
-        artifact = "io.dropwizard.metrics:metrics-graphite:4.0.7",
-        sha1 = "1b4f638d8d7474345337f2cb12da5c56ed4443b7",
+        artifact = "io.dropwizard.metrics:metrics-graphite:4.1.6",
+        sha1 = "9f7352925575904c3d3b6a085fc5a2c920c62275",
     )