Merge branch '5941-wrong-error-when-identity-is-spread-to-fd-from-sinaps-cannot-delete-non-existing-user-ldapuuid' into '1.4-dev'

Resolve "wrong error when Identity is spread to FD from SINAPS  "Cannot delete non-existing user {LDAPUUID}""

See merge request fusiondirectory/fd-plugins!522

(cherry picked from commit 2000d7c7)

b0b73671 🚑 fix(sinaps) Add missing casting to string