MRC: Remove "ping" on username mention

This appears to be something new that was added that is highly annoying to me and should never have been turned on by default.

This needs to be turned off. I'm also told that it can be configured by a template change. Not acceptable since messing with templates will mess with git.

This needs to be moved to a user configurable parameter whereby a user can choose if they want to be pinged when their nick is used.