Description: actually use the name argument

Not using it raises an exception

Author: Rebecca N. Palmer <rebecca_palmer@zoho.com>
Forwarded: https://pagure.io/pagure/pull-request/5514

--- a/pagure/ui/plugins.py
+++ b/pagure/ui/plugins.py
@@ -127,7 +127,7 @@ def view_plugin(repo, plugin, username=N
             flask.g.session.rollback()
             _log.exception("Could not add plugin %s", plugin.name)
             message = Markup(
-                "Could not add plugin,"
+                "Could not add plugin %s,"
                 ' please <a href="/about">contact an administrator</a>'
             )
             flask.flash(message % plugin.name)