Looong ago I told you Bette Midler waves bye-bye to “Hello, Dolly!” in January. With her salary plus percentage, she doesn’t need more bows, more bucks, or more pirouetting in high heels and tight corsets. Dec. 1, she’ll be 72, and just tumbled onstage mid-performance. Her people already consulted lawyers to determine if that flop — the tumble not the performance — is actionable. Like, to talk plain — when, which, who, what — can we sue over this.