fix #8010 - publish public key in webfinger

we were simply referring to the wrong key.
includes test

app/views/webfinger/search.xml.erb

@@ -2,6 +2,6 @@
 <XRD xmlns="http://docs.oasis-open.org/ns/xri/xrd-1.0">
   <Subject><%= @presenter.subject %></Subject>
   <%- @presenter.links.each do |rel, link| %>
-    <Link rel=<%=rel%> type=<%=link[:type]%> href="<%= link[:key] %>"/>
+    <Link rel=<%=rel%> type=<%=link[:type]%> href="<%= link[:href] %>"/>
   <% end %>
 </XRD>

test/functional/webfinger_controller_test.rb

@@ -15,11 +15,13 @@ class WebfingerControllerTest < ActionController::TestCase
   end
 
   test "get user webfinger xml" do
-    @user = stub_record :user, :public_key => 'my public key'
+    key = 'my public key'
+    @user = stub_record :user, :public_key => key
     User.stubs(:find_by_login).with(@user.login).returns(@user)
     get :search, :q => @user.email_address.to_s, :format => :xml
     assert_response :success
     assert_equal "application/xml", response.content_type
+    assert_includes response.body, Base64.encode64(key)
   end
 
   test "get user webfinger json" do