Why? I don't see any defects stating that name resolution doesn't work.
Have you had any community testing for this change?

@9037568 just put some white spaces into a tel number inside your address book on the fritz box ( like this '+49 40 123 456 789') and make a call from this number. the current version will not find a match because of the white spaces

Then don't put the whitespaces in.
I don't use or even have a fritzbox.

@9037568
its not forbidden to put white spaces into the tel numbers. it makes them even more readable. so why not?
most of the phones like for example iphone even add a white space automatically to separate the prefix of the tel number.
but why are you worried about the changes for a fritz box binding, if you even don't have one? :-)
or are u using the binding with another device, which supports the TR064 protocol?

Thanks, @kaikreuzer, for the confirmation.
Thanks for the patch, @andre77 !

This pull request has been mentioned on openHAB Community. There might be relevant details there:

https://community.openhab.org/t/fritzbox-tr064-binding-problem-resolving-external-call-number-to-name-with-a-google-synced-phonebook/39609/5