Launcher: Add screen_get_sel before choose selected screen to draw launcher.

src/launcher.c

@@ -43,6 +43,8 @@ launcher_execute(Launcher launcher)
      BarWindow *bw;
      Bool my_guitar_gently_wheeps = True;
 
+     screen_get_sel();
+
      int x = (infobar[selscreen].layout_button->geo.x
               + textw(tags[selscreen][seltag[selscreen]].layout.symbol) + PAD);
 

src/screen.c

@@ -138,7 +138,7 @@ screen_get_sel(void)
 {
      if(XineramaIsActive(dpy))
      {
-          /* Unused variables */
+          /* Unused variables (except x/y) */
           Window w;
           int d, u, x, y;