Changing owner information makes their pets disappear

[OlianasD]

When we change some information of an owner, their pets disappear from the PetClinic app. Tested on Windows 10, Java version 14.0.2, with both the integrated H2 database and MySQL.

Steps to reproduce:
Steps to reproduce:
-connect to the app -> Find owners -> Find owner
-George Franklin -> Edit owner
-set a new first name for the owner
-after clicking Update, the app shows the owner information page without the pets

[dsyer]

Fixed in d381fb6