Spelling error on events where max participation has been reached

[Former user]

The ComExA event, for example. says "The registrations are closed. The participant limited has been exceeded. "

It should be 'participant limit'

Not sure if this is the right space, but assuming this is hardcoded in the backend it'll be a backend fix

[Martijn Luinstra]

Fix spelling mistake when participant limit exceeded. Fixes #119

→ <<cset a68a94c11a8f>>