title: Serilog Filter Expression is not working to exclude the given endpoint logs
body: <p>I've a healthcheck endpoint in my .NetCore(2.2) WebAPI project for which I don't want to generate and write any logs. I'm writing the logs to WindowsEventLog. For that, I'm using a separate config file just for the logging purpose which I'm loading in my startup.</p>
  
  <p>This is the endpoint that I've in the controller for healthcheck:</p>
  
  <pre><code>[Route("healthcheck")] 
  [AllowAnonymous]
  public IActionResult Get()
  {
      return Ok("");
  }
  </code></pre>
  
  <p>This is how I'm loading the config file (SeriLogSettings.json) that I created for holding my Serilog configuration:</p>
  
  <pre><code> public Startup(IConfiguration configuration, IHostingEnvironment env)
          {
              var builder = new ConfigurationBuilder()
                 .SetBasePath(env.ContentRootPath)
                 .AddJsonFile("appsettings.json", optional: false, reloadOnChange: true)
                 .AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true)
                 .AddJsonFile("SeriLogSettings.json", optional: false)
                 .AddEnvironmentVariables();
  
              Configuration = builder.Build();
          }
  </code></pre>
  
  <p>And this is how my SerilogSettings.json looks like:</p>
  
  <pre><code>{
    "Serilog": {
      "Using": [ "Serilog.Settings.Configuration", "Serilog.Sinks.EventLog" ],
      "Filter": [
        {
          "Name": "ByExcluding",
          "Args": {
            "expression": "EndsWith(RequestPath, '%/healthcheck')"
          }
        }
      ],
      "MinimumLevel": {
        "Default": "Debug",
        "Override": {
          "Microsoft": "Warning",
          "System": "Warning"
        }
      },
      "Enrich": [ "FromLogContext" ],
      "WriteTo": [
        {
          "Name": "EventLog",
          "Args": {
            "source": "WebAPI", 
            "logName": "Application",
            "managedEventSource": true
          }
        }
      ],
      "Properties": {
        "Application": "ApplicationAPI"
      }
    }
  }
  </code></pre>
  
  <p>Despite using the ByExcluding expression to exclude the logs for /healthcheck endpoint, I'm getting the logs in the WindowsEventLog.
  I'm not able to fix why this is happening and not sure what am I doing wrong?</p>