Update test-configuration.json (#51591)

Retry Microsoft.AspNetCore.SignalR.Client.FunctionalTests.HubConnectionTests.ChangingUserNameDuringReconnectLogsWarning

Author: amcasey

eng/test-configuration.json

@@ -22,6 +22,7 @@
     {"testName": {"contains": "CertificateChangedOnDisk"}},
     {"testName": {"contains": "CertificateChangedOnDisk_Symlink"}},
     {"testName": {"contains": "CanLaunchPhotinoWebViewAndClickButton"}},
+    {"testName": {"contains": "ChangingUserNameDuringReconnectLogsWarning"}},
     {"testAssembly": {"contains": "IIS"}},
     {"testAssembly": {"contains": "Template"}},
     {"failureMessage": {"contains":"(Site is started but no worker process found)"}},