Fix regression from 69e32a6 when setting title.

x.c

@@ -1492,7 +1492,7 @@ void
 xsettitle(char *p)
 {
 	XTextProperty prop;
-	DEFAULT(p, "st");
+	DEFAULT(p, opt_title);
 
 	Xutf8TextListToTextProperty(xw.dpy, &p, 1, XUTF8StringStyle,
 			&prop);