OPS: check copyright year

[joe-chacko]

We need another condition here if there is a copyright but the year is not equal to the last change of the file.
This should be some other character (not TICK or CROSS) to indicate it MIGHT be ok — i.e. the committer needs to make the final decision whether that year needs updating. This should still return a non-zero return code so that GH flags it to any interested parties.

Originally posted by @joe-chacko in #209 (comment)