Fix login issue with Gerrit 3.6

Starting from Gerrit release 3.6 dependency to commons-lang was upgraded to
commons-lang3 in change 319919. Given that third party dependency still depends
on commons-lang we re-add commons-lang in this plugin.

Change-Id: If7d3d69bba10979a096bfef269e5bb6812f20f97

BUILD

diff --git a/BUILD b/BUILD
index 3454255..a13b9ed 100644
--- a/BUILD
+++ b/BUILD
@@ -9,6 +9,7 @@
     resources = glob(["src/main/resources/**"]),
     deps = [
         "@commons-collections//jar",
+        "@commons-lang//jar",
         "@cryptacular//jar",
         "@joda-time//jar",
         "@opensaml-core//jar",

external_plugin_deps.bzl

diff --git a/external_plugin_deps.bzl b/external_plugin_deps.bzl
index 59f0529..16b7dad 100644
--- a/external_plugin_deps.bzl
+++ b/external_plugin_deps.bzl
@@ -15,6 +15,12 @@
     )
 
     maven_jar(
+        name = "commons-lang",
+        artifact = "commons-lang:commons-lang:2.6",
+        sha1 = "0ce1edb914c94ebc388f086c6827e8bdeec71ac2",
+    )
+
+    maven_jar(
         name = "cryptacular",
         artifact = "org.cryptacular:cryptacular:1.2.1",
         sha1 = "c470bac7309ac04b0b9529bd7dcb1e0b75954f11",