Default TimeoutForFirmwareUpdate to Timeout (#1839)

* Default `TimeoutForFirmwareUpdate` to `Timeout`
Fixes #1838

MobiFlight/Board.cs

@@ -139,7 +139,7 @@ public class Connection
         /// <summary>
         /// Number of milliseconds to wait for the firmware update to complete before attempting to call GetInfo on the board.
         /// </summary>
-        public int TimeoutForFirmwareUpdate = 15000;
+        public int TimeoutForFirmwareUpdate;
     }
 
     /// <summary>
@@ -414,6 +414,23 @@ public void Migrate()
                     Info.FirmwareExtension = "hex";
                 }
             }
+
+            // Issue 1838:
+            // Handle undefined TimeoutForFirmwareUpdate by setting it to the value for Timeout.
+            if (Connection.TimeoutForFirmwareUpdate == 0)
+            {
+                // This test is required to ensure AvrDudeSettings actually exists. It may not, for example when
+                // loading a board.json file for something like a Pico.
+                if (AvrDudeSettings != null)
+                {
+                    Connection.TimeoutForFirmwareUpdate = AvrDudeSettings.Timeout != 0 ? AvrDudeSettings.Timeout : 15000;
+                }
+                else
+                {
+                    Connection.TimeoutForFirmwareUpdate = 15000;
+                }
+            }
+
         }
 #pragma warning restore CS0612 // Type or member is obsolete