Square brackets missing when `/get_wireguard_credentials` via TG

[mateumiralles]

When setting up the Dappnode Cloud instance, the linked Telegram bot, using the /get_wireguard_credentials command produces an output where the information is correct, but the square brackets for Interface and Peer are missing. Update the output to include these brackets so users can directly copy and paste the content into the wireguard.conf file without needing to make manual edits.