Fix icon in Cannot Delete Event message

When the tutorial is on you are not allowed to delete an event. When a user attempts to delete the event they will receive the appropriate warning saying the "Event deletion is disabled while in tutorial mode. Please turn off tutorial first."

The problem is there is an exclamation point that appears before the beginning of the sentence. I'm not sure if this was supposed to be a graphic for the warning symbol in which there would typically be a yellow triangle around it or if it was accidentally added to the text.