Upgrade javamelody-core to 1.91.0

Change-Id: I36ee04b502826875850abd64d736eefe3526c02b
diff --git a/external_plugin_deps.bzl b/external_plugin_deps.bzl
index 0244943..684b16a 100644
--- a/external_plugin_deps.bzl
+++ b/external_plugin_deps.bzl
@@ -3,8 +3,8 @@
 def external_plugin_deps():
     maven_jar(
         name = "javamelody-core",
-        artifact = "net.bull.javamelody:javamelody-core:1.90.0",
-        sha1 = "b769cc9be4a7b95ea7901c573ebc37e84cbe8525",
+        artifact = "net.bull.javamelody:javamelody-core:1.91.0",
+        sha1 = "e708e7850f3a9929c287bc4cd670551ed3af572f",
     )
 
     maven_jar(