fix nuget target

MediaBrowser.Server.Mono/MediaBrowser.Server.Mono.csproj

@@ -195,11 +195,4 @@
     </None>
   </ItemGroup>
   <ItemGroup />
-  <Import Project="..\packages\SkiaSharp.1.58.1\build\net45\SkiaSharp.targets" Condition="Exists('..\packages\SkiaSharp.1.58.1\build\net45\SkiaSharp.targets')" />
-  <Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
-    <PropertyGroup>
-      <ErrorText>This project references NuGet package(s) that are missing on this computer. Use NuGet Package Restore to download them.  For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}.</ErrorText>
-    </PropertyGroup>
-    <Error Condition="!Exists('..\packages\SkiaSharp.1.58.1\build\net45\SkiaSharp.targets')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\SkiaSharp.1.58.1\build\net45\SkiaSharp.targets'))" />
-  </Target>
 </Project>