fix(db): throw readable error when creating _id with background: true

Author: mbroadst

lib/operations/db_ops.js

@@ -278,13 +278,15 @@ function createIndex(db, name, fieldOrSpec, options, callback) {
      * 86 = 'IndexKeySpecsConflict' (index already exists with the same name)
      * 11000 = 'DuplicateKey' (couldn't build unique index because of dupes)
      * 11600 = 'InterruptedAtShutdown' (interrupted at shutdown)
+     * 197 = 'InvalidIndexSpecificationOption' (`_id` with `background: true`)
      */
     if (
       err.code === 67 ||
       err.code === 11000 ||
       err.code === 85 ||
       err.code === 86 ||
-      err.code === 11600
+      err.code === 11600 ||
+      err.code === 197
     ) {
       return handleCallback(callback, err, result);
     }