As far as I know... no.
Question is, why would you want to remove it? If the repeater owner some day decided to check their requests and answer, then you would finally get what you were asking for. If they don't ever answer, well, nothing has changed one way or another.
I understand and agree that it would be nice to clear it so you don't even have to look at it again, and I'm not sure why it isn't an option. But I guess it lets you keep track of repeaters you never have to bother asking permission for eveyr again because it seems no one is answering it anyway.