upload: don't ask for password if the env var is empty string

Related to rhbz#1066486

Signed-off-by: Jakub Filak <jfilak@redhat.com>
lib: fix a bug in ureport response parser

Revealed by coverity

Related to rhbz1139987

Signed-off-by: Jakub Filak <jfilak@redhat.com>