Maybe the following workaround may do it :
The idea is to identify movies that have at least one person without person imdb url and then update those movies so that persons imdb url are 'refreshed'.
To be done first on a TEST (copied) database...
Step by step :
- Import (hit 'import' and copy/paste) following query into ExtraQueries plugin
- Use export button to get the list into excel for instance
- copy/paste that Ids list into add movie window
-> this will bulk download movie data (and, as a consequence, persons imdb urls) for movies having at least one person without imdb url...
Please let me know if it did the job.