esx: Accept empty "path" URI component same way as "/"

esx: Accept empty "path" URI component same way as "/"

When connecting to "esx://" URI there's code which prints a warning that
the path is not "empty". The check validates that "uri->path" is "/".

In case when the user uses URI such as:

 esx://hostname

the warning is printed as well. Since there is no effective difference
betweeen the two allow empty strings as well.

Resolves: https://issues.redhat.com/browse/RHEL-86459
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>