patch 8.0.0274: possible recursive screen updating causes trouble

Problem:    When update_single_line() is called recursively, or another screen
            update happens while it is busy, errors may occur.
Solution:   Check and update updating_screen. (Christian Brabandt)

src/version.c

@@ -764,6 +764,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    274,
 /**/
     273,
 /**/