bug#56481: Weird error message on C-x C-s in customize window when nothing is changed

[Emily Seville]

Emacs: 27.1

Steps to reproduce:

1. M-x customize
   
2. Type numbers in search and press enter
   
3. C-x C-s and type yes and obtain this error:

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# Best regards, Emily Grace Seville.

[contacts]

site = "https://github.com/EmilySeville7cfg"

phone = "+79245201384"