Set PYTHONUNBUFFERED for systemd managed python

This lets python scripts print to the journal.

Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/meta-phosphor/common/recipes-phosphor/dbus/obmc-mapper/obmc-mapper.service b/meta-phosphor/common/recipes-phosphor/dbus/obmc-mapper/obmc-mapper.service
index 05d1e80..ff863ea 100644
--- a/meta-phosphor/common/recipes-phosphor/dbus/obmc-mapper/obmc-mapper.service
+++ b/meta-phosphor/common/recipes-phosphor/dbus/obmc-mapper/obmc-mapper.service
@@ -7,6 +7,7 @@
 ExecStart=/usr/sbin/phosphor-mapper
 BusName=org.openbmc.ObjectMapper
 TimeoutStartSec=300
+Environment="PYTHONUNBUFFERED=1"
 
 [Install]
 WantedBy=multi-user.target