removed unnecessary package ref

Author: MV10

src/Serilog.Settings.Configuration/Serilog.Settings.Configuration.csproj

@@ -27,13 +27,10 @@
   </ItemGroup>
 
   <ItemGroup Condition="'$(TargetFramework)' == 'net451'">
-    <PackageReference Include="Microsoft.Extensions.Configuration.Abstractions" Version="1.1.2" />
     <PackageReference Include="Microsoft.Extensions.Options.ConfigurationExtensions" Version="1.1.2" />
   </ItemGroup>
 
   <ItemGroup Condition="('$(TargetFramework)' == 'netstandard2.0') Or ('$(TargetFramework)' == 'net461')">
-    <PackageReference Include="Microsoft.Extensions.Configuration.Abstractions" Version="2.0.1" />
     <PackageReference Include="Microsoft.Extensions.Options.ConfigurationExtensions" Version="2.0.0" />
   </ItemGroup>
-
 </Project>