added reference to playlist icon

MediaBrowser.WebDashboard/MediaBrowser.WebDashboard.csproj

@@ -123,6 +123,9 @@
     <Content Include="dashboard-ui\css\images\items\list\video.png">
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
     </Content>
+    <Content Include="dashboard-ui\css\images\media\playlist.png">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </Content>
     <Content Include="dashboard-ui\css\images\media\queue.png">
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
     </Content>