Update commands_vector_sets.json to support the new WITHATTRIBS option for VSIM (#874)

Author: mingdaoy

hack/cmds/commands_vector_sets.json

@@ -313,6 +313,11 @@
         "type": "command",
         "optional": true
       },
+      {
+        "command": "WITHATTRIBS",
+        "type": "command",
+        "optional": true
+      },
       {
         "command": "COUNT",
         "name": "num",