Remove StackTrace from EventSource Message

When logging connection exception information to the EventSoruce we are putting the full exception ToString in the Message which clutters it to the users.

Instead, just put the Exception.Message in the EventSource event message. The full exception information comes in the details of the EventSource event.

Fix #1493

Author: eerhardt

projects/RabbitMQ.Client/client/api/ShutdownEventArgs.cs

@@ -123,17 +123,34 @@ public Exception Exception
         /// </summary>
         public string ReplyText { get; private set; }
 
-        /// <summary>
-        /// Override ToString to be useful for debugging.
-        /// </summary>
-        public override string ToString()
+        private string GetMessageCore()
         {
             return $"AMQP close-reason, initiated by {Initiator}"
                 + $", code={ReplyCode}"
                 + (ReplyText != null ? $", text='{ReplyText}'" : string.Empty)
                 + $", classId={ClassId}"
                 + $", methodId={MethodId}"
-                + (Cause != null ? $", cause={Cause}" : string.Empty)
+                + (Cause != null ? $", cause={Cause}" : string.Empty);
+        }
+
+        /// <summary>
+        /// Gets a message suitable for logging.
+        /// </summary>
+        /// <remarks>
+        /// This leaves out the full exception ToString since logging will include it separately.
+        /// </remarks>
+        internal string GetLogMessage()
+        {
+            return GetMessageCore()
+                + (_exception != null ? $", exception={_exception.Message}" : string.Empty);
+        }
+
+        /// <summary>
+        /// Override ToString to be useful for debugging.
+        /// </summary>
+        public override string ToString()
+        {
+            return GetMessageCore()
                 + (_exception != null ? $", exception={_exception}" : string.Empty);
         }
     }

projects/RabbitMQ.Client/client/impl/Connection.cs

@@ -455,16 +455,17 @@ public void HandleDomainUnload(object sender, EventArgs ea)
 
         public void HandleMainLoopException(ShutdownEventArgs reason)
         {
+            string message = reason.GetLogMessage();
             if (!SetCloseReason(reason))
             {
-                LogCloseError($"Unexpected Main Loop Exception while closing: {reason}", reason.Exception);
+                LogCloseError($"Unexpected Main Loop Exception while closing: {message}", reason.Exception);
                 return;
             }
 
             _model0.MaybeSetConnectionStartException(reason.Exception);
 
             OnShutdown();
-            LogCloseError($"Unexpected connection closure: {reason}", reason.Exception);
+            LogCloseError($"Unexpected connection closure: {message}", reason.Exception);
         }
 
         public bool HardProtocolExceptionHandler(HardProtocolException hpe)