version.c: update N/A. #4660

vim-patch:7.4.1562 is N/A because do_helptags(..) no longer has a dirname
argument and dirname is explicitly allocated in the method body, so it must be
freed.

Helped-by: oni-link

src/nvim/version.c

@@ -116,7 +116,7 @@ static int included_patches[] = {
   // 1565,
   // 1564,
   // 1563,
-  // 1562,
+  // 1562 NA
   // 1561 NA
   // 1560,
   // 1559,