vim-patch: Mark patch 7.4.560 as NA

The memory leak fixed in 7.4.560 was fixed in
e10670ac3b. We also do not need to keep
`y_current->y_array` as is until done, because our memory allocations
cannot fail.

src/nvim/version.c

@@ -178,7 +178,7 @@ static char *(features[]) = {
 };
 
 static int included_patches[] = {
-  //560,
+  //560 NA
   //559,
   //558 NA
   //557 NA