ref@mypage.sk

There it a file that ensures that „svn“ commands use the credentials in file.
When you manually call svn with different user this gets forgotten.
It can be renowed by calling:

cp subversion-auth-svn-simple-b74f483b92e17c928970eadd0f874d61-with-pwd .subversion/auth/svn.simple/b74f483b92e17c928970eadd0f874d61
content of the file:
K 8
passtype
V 6
simple
K 15
svn:realmstring
V 53
<https://svn.sail-labs.com:443> Subversion repository
K 8
username
V 16  (length in letters)
this-is-the-user
K 8
password
V 20 (length in letters)
this-is-the-password
END