Fix ClipperException

Author: JimBobSquarePants

src/ImageSharp.Drawing/ImageSharp.Drawing.csproj

@@ -15,10 +15,6 @@
     <TargetFrameworks>netcoreapp3.1;netcoreapp2.1;netstandard2.1;netstandard2.0;netstandard1.3;net472</TargetFrameworks>
   </PropertyGroup>
 
-  <ItemGroup>
-    <Compile Remove="Shapes\PolygonClipper\ClipperException.cs" />
-  </ItemGroup>
-
   <ItemGroup>
     <None Include="..\..\shared-infrastructure\branding\icons\imagesharp.drawing\sixlabors.imagesharp.drawing.128.png" Pack="true" PackagePath="" />
   </ItemGroup>