patch 7.4.731

Problem:    The tab menu shows "Close tab" even when it doesn't work.
Solution:   Don't show "Close tab" for the last tab. (John Marriott)

src/version.c

@@ -741,6 +741,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    731,
 /**/
     730,
 /**/