1) MCEdit (A free world editor for Minecraft, just type it into your
preferred search engine and you will find it no worries, there are also
tonnes of tutorials and "how-to" videos as well should you need a hand
working out how to use it.)
2) The world file that contains the corrupted chunk.
Once
you have these 2 things the next part is a piece of cake, simply open
the world file that has the chunk issue with MCEdit. Press these keys-
"Ctrl+I" and then select the option of "region repair" (Or something
along those lines, I cannot remember exactly what the option is called,
but it is only 1 of 2 options that are available.) and then let it work
its magic!
Re upload the file to your server or open it in Single
player (depending on how you play I suppose lol) and it should never
bother you again. I have personally tried this method and it is safe to
say it has been a success for me and my server!