update table schema

Author: hernandezc1

broker/setup_broker/lsst/templates/bq_lsst_alerts_v7_1_schema.json

@@ -2436,12 +2436,6 @@
             "name": "r_Ndata",
             "type": "INTEGER"
           },
-          {
-            "description": "Unique identifier.",
-            "mode": "NULLABLE",
-            "name": "u_Chi2",
-            "type": "FLOAT"
-          },
           {
             "description": "Best fit absolute magnitude (i band).",
             "mode": "NULLABLE",