Bump NLog from 4.7.6 to 4.7.7 in /src/NLog.Web (#629)

Bumps [NLog](https://github.com/NLog/NLog) from 4.7.6 to 4.7.7.
- [Release notes](https://github.com/NLog/NLog/releases)
- [Changelog](https://github.com/NLog/NLog/blob/dev/CHANGELOG.md)
- [Commits](https://github.com/NLog/NLog/commits)

Signed-off-by: dependabot[bot] <support@github.com>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

src/NLog.Web/NLog.Web.csproj

@@ -44,7 +44,7 @@ For ASP.NET Core: Check https://www.nuget.org/packages/NLog.Web.AspNetCore
     <DownloadFile SourceUrl="https://nlog-project.org/N.png" DestinationFolder="$(MSBuildThisFileDirectory)" />
   </Target>
   <ItemGroup>
-    <PackageReference Include="NLog" Version="4.7.6" />
+    <PackageReference Include="NLog" Version="4.7.7" />
   </ItemGroup>
   <ItemGroup>
     <Reference Include="System.Web" />