Fix package icon

Author: alistairjevans

src/Autofac.Multitenant/Autofac.Multitenant.csproj

@@ -14,6 +14,7 @@
     <PackageTags>autofac;di;ioc;dependencyinjection</PackageTags>
     <PackageReleaseNotes>Release notes are at https://github.com/autofac/Autofac.Multitenant/releases</PackageReleaseNotes>
     <PackageProjectUrl>https://autofac.org</PackageProjectUrl>
+    <PackageIcon>icon.png</PackageIcon>
     <PackageLicenseExpression>MIT</PackageLicenseExpression>
     <RepositoryType>git</RepositoryType>
     <RepositoryUrl>https://github.com/autofac/Autofac.Multitenant</RepositoryUrl>