switch lock from image to icon

MediaBrowser.WebDashboard/MediaBrowser.WebDashboard.csproj

@@ -781,9 +781,6 @@
     <Content Include="dashboard-ui\collections.html">
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
     </Content>
-    <Content Include="dashboard-ui\css\images\editor\lock.png">
-      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
-    </Content>
     <Content Include="dashboard-ui\css\images\editor\missing.png">
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
     </Content>