Fixed context menu crash.

Thanks .NET C# for not remembering what control triggered the context menu in the first place.

Touhou Launcher/MainForm.cs

@@ -597,7 +597,7 @@ private void trayMenu_Opening(object sender, CancelEventArgs e)
 
         private void configureToolStripMenuItem_Click(object sender, EventArgs e)
         {
-            Button btn = (Button)((ContextMenuStrip)((ToolStripMenuItem)sender).GetCurrentParent()).SourceControl;
+            Button btn = (Button)((ContextMenuStrip)((ToolStripMenuItem)sender).GetCurrentParent()).Tag;
             ConfigForm gameConfig = new ConfigForm(btn);
             gameConfig.ShowDialog();
         }