Paul McMann, a Boston builder who got on the wrong side of a former client will just have to suck it up and live with her online gripes about his services. Public Citizen, which represents the woman, won its case in front of an arbitrator who hears disputes about Internet domains. McMann has already sued three other times to have her sites — PaulMcMannSucks.com and PaulMcMann.com — taken down. He has lost twice, while the third suit is pending. The use of the URLs and her criticisms posted there are protected under the First Amendment, said Public Citizen attorney Greg Beck.