Upgrade metrics-graphite to 4.1.12.1

To align with the version used in core Gerrit's stable-3.2 branch.

Change-Id: Ie088d5f44eade1be9469897682027625a707549e
diff --git a/external_plugin_deps.bzl b/external_plugin_deps.bzl
index 91f67b2..c990e1c 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:4.1.6",
-        sha1 = "9f7352925575904c3d3b6a085fc5a2c920c62275",
+        artifact = "io.dropwizard.metrics:metrics-graphite:4.1.12.1",
+        sha1 = "f7a5ef6ac15eee9af221d052821d12a08bf8bcdf",
     )