A break in a main at 126th Street has cut off the water supply to Shea Stadium, prompting an indefinite delay to the start of today’s game between the Mets and Pirates. The teams are not in the dugouts as of 1:05 p.m., and the only personnel on the field are security guards. A limp hose used to water the mound rests in the infield grass, and all of the bases are dislodged. Hmmm, this could take a while …