patch 8.0.1450: GUI: endless loop when stopping cursor blinking

Problem:    Endless loop when gui_mch_stop_blink() is called while blink_state
            is BLINK_OFF. (zdohnal)
Solution:   Avoid calling gui_update_cursor() recursively.
diff --git a/src/proto/gui_mac.pro b/src/proto/gui_mac.pro
index c7ab982..011ef28 100644
--- a/src/proto/gui_mac.pro
+++ b/src/proto/gui_mac.pro
@@ -17,7 +17,7 @@
 int gui_mch_is_blinking(void);
 int gui_mch_is_blink_off(void);
 void gui_mch_set_blinking(long wait, long on, long off);
-void gui_mch_stop_blink(void);
+void gui_mch_stop_blink(int may_call_gui_update_cursor);
 void gui_mch_start_blink(void);
 void gui_mch_getmouse(int *x, int *y);
 void gui_mch_setmouse(int x, int y);