计量台账，变更后计算，兼容变更清单bwmx无法定位的情况

app/public/js/stage.js

@@ -1565,7 +1565,7 @@ $(document).ready(() => {
                     if (posData && posData.length > 0) {
                         for (const p of changeBills.pos) {
                             const changePos = p.bwmx ? posData.find(x => { return x.name === p.bwmx; }) : posData[0];
-                            changePos.tz_qc_qty = ZhCalc.add(changePos.tz_qc_qty, p.checked_amount);
+                            if (changePos) changePos.tz_qc_qty = ZhCalc.add(changePos.tz_qc_qty, p.checked_amount);
                         }
                     }
                 }