I am playing the 1.7.10 minecraft version 1.7.10-r21 of ActuallyAdditions and it's the most recent version for this pack for 1.7.10. Although it does give me a notification that there is an update for 1.11-r89.
Which is pointless since I am playing on a 1.7.10 pack?
Can this be removed?

No, it can't be removed, but it can be disabled in the config via the "Version Specific Update Checker" option.