Handle the case where 'vtable-update-object' doesn't find old object

* lisp/emacs-lisp/vtable.el (vtable-update-object): If OLD-OBJECT
is not found, don't call ELT, since SEQ-POSITION may return nil.
(Bug#69664)
2 jobs for master in 103 minutes and 49 seconds (queued for 27 seconds)
Status Job ID Name Coverage
  Build Images
failed #82540
build-image-inotify

01:43:49

 
  Normal
skipped #82541
test-lisp-emacs-lisp-inotify
 
Name Stage Failure
failed
build-image-inotify Build Images
Running after_script
Running after script...
$ test -n "$(docker ps -aq -f name=${test_name})" && docker cp ${test_name}:checkout/test ${test_name}
$ test -n "$(docker ps -aq -f name=${test_name})" && docker rm ${test_name}
$ find ${test_name} ! \( -name "*.log" -o -name ${EMACS_TEST_JUNIT_REPORT} \) -type f -delete
find: build-image-inotify-c94d680f: No such file or directory
WARNING: after_script failed, but job will continue unaffected: exit code 1
Cleaning up project directory and file based variables
ERROR: Job failed: exit code 1