Not if it still works! Rubber duck antennas are nothing but a rubber enclosed coiled lenght of wire. You can bend it back straight too, without harming it. Check the SMA mount on the radio however, and make sure it's not cracked.
Yeah, it's only a wire inside ,the wire is caste in plastic then by a rubber. If you reall really bent it, like it's totally changed shape then time to worry. Hopfully it's not a seeker!?
No problem, straighten it out. You might have to bend it past the point of being straight, because it will spring back some. Just try a little at a time, you won't hurt it.