patch 7.4.1881

Problem:    Appending to a long quickfix list is slow.
Solution:   Add qf_last.

src/version.c

@@ -753,6 +753,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1881,
 /**/
     1880,
 /**/