MAVLinkInterface: apply theme to progress form

The theme would show correctly for the main connection button, but if
anything else, like ConnectionOptions, launched the connection, the
progress bar would show up unthemed.

Program.cs

@@ -382,7 +382,11 @@ public static void Start(string[] args)
 
             // generic status report screen
             MAVLinkInterface.CreateIProgressReporterDialogue += title =>
-                new ProgressReporterDialogue() {StartPosition = FormStartPosition.CenterScreen, Text = title};
+            {
+                var ret = new ProgressReporterDialogue() {StartPosition = FormStartPosition.CenterScreen, Text = title};
+                ThemeManager.ApplyThemeTo(ret);
+                return ret;
+            };
 
             Console.WriteLine("Setup proxy");
             try