patch 9.0.1428: cursor in wrong position when leaving insert mode

Problem:    Cursor in wrong position when leaving insert mode.
Solution:   Update the w_valid flags.  Position the cursor also when not
            redrawing. (closes #12137)
diff --git a/src/main.c b/src/main.c
index d1c42ed..f5d3cb4 100644
--- a/src/main.c
+++ b/src/main.c
@@ -305,7 +305,7 @@
 	params.want_full_screen = FALSE;
 
     /*
-     * When certain to start the GUI, don't check capabilities of terminal.
+     * When certain to start the GUI, don't check terminal capabilities.
      * For GTK we can't be sure, but when started from the desktop it doesn't
      * make sense to try using a terminal.
      */
@@ -1290,7 +1290,11 @@
 	 * update cursor and redraw.
 	 */
 	if (skip_redraw || exmode_active)
+	{
 	    skip_redraw = FALSE;
+	    setcursor();
+	    cursor_on();
+	}
 	else if (do_redraw || stuff_empty())
 	{
 #ifdef FEAT_GUI