The opening curly brace, '{', is a regex reserved control character, so it needs to be escaped (see http://stackoverflow.com/a/400316/1106367)
Minor improvements:
no need to sort the whole list if all we need is the maximum element, also instead of reinventing the wheel we can use utils to get indices from qualities.
Merge pull request #2953 from codesparkle/ndr-regexes-escape-correctly

[ndr] fix regexes containing illegal characters