patch 7.4.1899

Problem:    GTK 3: cursor blinking doesn't work well.
Solution:   Instead of gui_gtk_window_clear() use gui_mch_clear_block().
            (Kazunobu Kuriyama)

src/version.c

@@ -753,6 +753,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1899,
 /**/
     1898,
 /**/