Bump log4net in /Extensions/Xtensive.Orm.Logging.log4net

Bumps [log4net](https://github.com/apache/logging-log4net) from 2.0.8 to 2.0.10.
- [Release notes](https://github.com/apache/logging-log4net/releases)
- [Changelog](https://github.com/apache/logging-log4net/blob/master/ReleaseInstructions.txt)
- [Commits](apache/logging-log4net@rel/2.0.8...rel/2.0.10)

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Author: dependabot[bot]

Extensions/Xtensive.Orm.Logging.log4net/Xtensive.Orm.Logging.log4net.csproj

@@ -13,7 +13,7 @@
     <AssemblyOriginatorKeyFile>$(ExtensionsKeyFile)</AssemblyOriginatorKeyFile>
   </PropertyGroup>
   <ItemGroup>
-    <PackageReference Include="log4net" Version="2.0.8" />
+    <PackageReference Include="log4net" Version="2.0.10" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\..\Orm\Xtensive.Orm\Xtensive.Orm.csproj" />