I must have sat in the theater at least twenty five times in 1977. Add to that the repeated viewings of my laser disc in the 1980s and I've heard the line where Leia mentioned the clone wars more times than I can count. I never once gave it a moment of thought.
It was something from the past that only she understood. It wasn't integral to the adventure I was on in the theater, nor was it of any importance to the people in the story.
It was there to establish that Ben was someone from her father's past. It didn't need to be explained. Fortunately for me, thirty seven years later it remains an unimportant mystery.