add class for systray

chadwm/dwm.c

@@ -604,6 +604,8 @@ clientmessage(XEvent *e)
 			updatesystrayicongeom(c, wa.width, wa.height);
 			XAddToSaveSet(dpy, c->win);
 			XSelectInput(dpy, c->win, StructureNotifyMask | PropertyChangeMask | ResizeRedirectMask);
+                        XClassHint ch = {"dwmsystray", "dwmsystray"};
+			XSetClassHint(dpy, c->win, &ch);
 			XReparentWindow(dpy, c->win, systray->win, 0, 0);
 			/* use parents background color */
 			swa.background_pixel  = scheme[SchemeNorm][ColBg].pixel;