Only logging "Client will now throw an _MqttConnectingFailedException_."...

Only logging "Client will now throw an _MqttConnectingFailedException_." warning when actually throwing the exception (#1801)

* Warning was always logged

Warning was always logged while the text states it would throw a `MqttConnectingFailedException` exception

* Update ReleaseNotes.md

---------
Co-authored-by: NChristian <6939810+chkr1011@users.noreply.github.com>

.github/workflows/ReleaseNotes.md

 * [Client] Fixed _PlatformNotSupportedException_ when using Blazor (#1755, thanks to @Nickztar).
+* [Client] Fixed wrong logging of obsolete feature when connection was not successful (#1801, thanks to @ramonsmits).
 * [Client] Fixed _NullReferenceException_ when performing several actions when not connected (#1800, thanks to @ramonsmits).
 * [Server] Fixed _NullReferenceException_ in retained messages management (#1762, thanks to @logicaloud).
 * [Server] Exposed new option which allows disabling packet fragmentation (#1753).

Source/MQTTnet/Client/MqttClient.cs

@@ -465,11 +465,10 @@ namespace MQTTnet.Client
             // did send a proper ACK packet with a non success response.
             if (options.ThrowOnNonSuccessfulConnectResponse)
             {
-                _logger.Warning(
-                    "Client will now throw an _MqttConnectingFailedException_. This is obsolete and will be removed in the future. Consider setting _ThrowOnNonSuccessfulResponseFromServer=False_ in client options.");
-
                 if (result.ResultCode != MqttClientConnectResultCode.Success)
                 {
+                    _logger.Warning(
+                        "Client will now throw an _MqttConnectingFailedException_. This is obsolete and will be removed in the future. Consider setting _ThrowOnNonSuccessfulResponseFromServer=False_ in client options.");
                     throw new MqttConnectingFailedException($"Connecting with MQTT server failed ({result.ResultCode}).", null, result);
                 }
             }
@@ -1060,4 +1059,4 @@ namespace MQTTnet.Client
             }
         }
     }
-}
\ No newline at end of file
+}