fixes #1581 - Metadata Manager: Disable display of "MissingTrailer" icon

MediaBrowser.WebDashboard/MediaBrowser.WebDashboard.csproj

@@ -796,9 +796,6 @@
     <Content Include="dashboard-ui\css\images\editor\missingprimaryimage.png">
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
     </Content>
-    <Content Include="dashboard-ui\css\images\editor\missingtrailer.png">
-      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
-    </Content>
     <Content Include="dashboard-ui\css\metadataeditor.css">
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
     </Content>