tramp-default-user

tramp-default-user is a variable defined in `tramp.el'.
Its value is

nil

Documentation:
Default user to use for transferring files.
It is nil by default; otherwise settings in configuration files like
"~/.ssh/config" would be overwritten. Also see `tramp-default-user-alist'.

This variable is regarded as obsolete, and will be removed soon.

You can customize this variable.