[Pgadmin] [Docker] servers.json import fails when running indesktop mode

Hi,

When running the docker image in desktop mode (PGADMIN_CONFIG_SERVER_MODE=False), no user is created. That is expected
behaviour.
But then the code that imports the servers.json pre-configuration fails as it ties the import to the default user.

I think line 40 of entrypoint.sh
(https://git.postgresql.org/gitweb/?p=pgadmin4.git;a=blob;f=pkg/docker/entrypoint.sh;h=47d14bf2d415777c64b221fb1fc75d61c5e3cecc;hb=HEAD)
shouldnot specify a user when running in dekstop mode.  
I tested it without --user parameter and it successfully imported the servers.json configuration.

Should I submit a patch ? First time contributing to Pgadmin :)

Regards,
Olivier Levitt