view date repeats : shown even if only one date

I have looked all D7 issues related to Date Repeat before posting this issue.

The permission "view date repeats" always shows the tab even if there is only one date.

It would be a nifty option, but I have forced not to use it since it becomes more clutter than useful for visitors.

I tried to add a new permission for the sub-module date_repeat_field, but I'm not great at PHP.