JOHN Rzeznik is in pragmatic mood.Odd really for someone who thinks they have just made the album of their career.Magnetic, the tenth release from the Goo Goo Dolls, could be the last, he says.It's not terminal, theres no suggestion of creative differences, the need for band members to find themselves and explore other avenues.If anything the whole process has been hugely rewarding.Rzeznik is simply facing up to reality."I think it's a very positive, upbeat record," he said, the enthusiasm clear in his voice. "I just wanted to have a good time making an album because I suddenly realised