Kristaps Porzingis will miss his second straight game Monday in Charlotte with a sore left knee, as he still is feeling mild pain. It’s the sixth game he’s missed this season — he also sat out the second half of two others — because of ailments. Porzingis tested his left knee at Monday’s shootaround and still didn’t feel 100 percent. He will have two days off and is expected to be back for the Knicks’ game against the Celtics on Thursday at the Garden. “He’s still felt like he did the other night,’’ Knicks coach Jeff Hornacek said. “He went through shootaround, went through same routine as Saturday and still felt it.”