journal: bump default log level for stream() to INFO
journal: bump default log level for stream() to INFO

By default debug messages are ignored, and INFO should be used for
"normal" messages.

systemd/python-systemd,Awesense/python-systemd,systemd/python-systemd,Awesense/python-systemd,keszybz/python-systemd,keszybz/python-systemd,Awesense/python-systemd