patch 7.4.1890

Problem:    GUI: When channel data is received the cursor blinking is
            interrupted.  (Ramel Eshed)
Solution:   Don't update the cursor when it is blinking.

src/gui_gtk_x11.c

@@ -810,6 +810,12 @@ gui_gtk_is_blink_on(void)
 }
 #endif
 
+    int
+gui_mch_is_blinking(void)
+{
+    return blink_state != BLINK_NONE;
+}
+
     void
 gui_mch_set_blinking(long waittime, long on, long off)
 {