Add missing entries in manifest when using BUCK build

Implementation-Title and Implementation-URL were missing when building
with Buck instead of Maven.

Change-Id: I4ebefd0e091ca58f27513db676764aea559eab06

BUCK

diff --git a/BUCK b/BUCK
index 939d516..17b8fee 100644
--- a/BUCK
+++ b/BUCK
@@ -4,6 +4,8 @@
   resources = glob(['src/main/resources/**/*']),
   manifest_entries = [
     'Gerrit-PluginName: admin-console',
-    'Gerrit-SshModule: com.googlesource.gerrit.plugins.adminconsole.AdminConsoleCommandModule'
+    'Gerrit-SshModule: com.googlesource.gerrit.plugins.adminconsole.AdminConsoleCommandModule',
+    'Implementation-Title: Plugin admin-console',
+    'Implementation-URL: https://gerrit-review.googlesource.com/#/admin/projects/plugins/admin-console',
   ]
 )