(Reuters) -One of three Minneapolis policemen who watched fellow officer Derek Chauvin kill George Floyd by kneeling on his neck pleaded guilty to aiding and abetting manslaughter in the 2020 case, which triggered a wave of protests over racial injustice. Chauvin, who is white, was sentenced to 22-1/2 years in prison last year after his conviction on charges of murdering Floyd, a Black man suspected of passing a counterfeit bill. By entering the plea on Wednesday, now-former officer Thomas Lane avoided an upcoming trial on the more serious charge of aiding and abetting second-degree murder. He…