vim-patch: Mark patch 7.4.560 as NA

The memory leak fixed in 7.4.560 was fixed in
e10670ac3bccbea707432bdb54e18639cf2e125f. We also do not need to keep
`y_current->y_array` as is until done, because our memory allocations
cannot fail.
Merge pull request #1743 from oni-link/vim.patch.7.4.560

vim-patch: Mark patch 7.4.560 as NA