Trusted domain config.php edit probleme on synology


I just install Nexcloud on my synology and everything works fine apart the part to add a trusted domain.

When i do an ssh and i use “sudo vi config.php”, i edit the file i put my domain and i save. Then the modification is not done and when i try to edit again i have :

Found a swap file by the name “.config.php.swp”
owned by: root dated: Fri Jul 3 11:58:56 2020
file name: /volume1/web/nextcloud/config/config.php
modified: YES
user name: root host name: JON
process ID: 25877
While opening file “config.php”
dated: Tue Jul 7 17:51:37 2020
NEWER than swap file!

(1) Another program may be editing the same file. If this is the case
be careful not to end up with two different instances of the same
file when making changes. Quit, or continue with caution.
(2) An edit session for this file crashed.
If this is the case, use “:recover” or “vim -r config.php”
to recover the changes (see “:help recovery”).
If you did this already, delete the swap file “.config.php.swp”
to avoid this message.

Swap file “.config.php.swp” already exists!
[O]pen Read-Only, (E)dit anyway, ®ecover, (D)elete it, (Q)uit, (A)bo
rt "

I also tried to edit / reboot and i have the same
How can i edit this file and save it ?