fix #H4028 - ':' sometimes doesn't work

fix #H4028 - ':' sometimes doesn't work

User had
MSGTTYPE=norep "You see here"
and complained that once the message had been given while walking
over an object, using ':' to intentionally look at something would
end up doing nothing if its feedback was a repeat of "You see here".

Trying to classify which actions should deliberately override
no-repeat (or no-show) will be an ordeal.  This fixes the case for
the ':' command where the user obviously expects feedback.  I think
it could be done better but am settling for something quick and easy.