Auto-completion of #channel name does not disappear if there are no matches #622
Description
When chatting about channels of other irc servers, or anything starting with #, Rocket.Chat starts trying to autocomplete what we're typing. When nothing matches a Rocket.Chat #channel, the box will stay popped up, but if you simply hit enter to finish the message, it will replace the word with #general. We're used to Slack's approach which is if no #channel matches, then assume the user doesn't want to auto-complete and allow the user to finish typing without getting in the way.