SCRIPTS: Make snmpscrape.py get the 1.3.6.1.4 subtree as well

The halting of a vanilla snmpwalk run is at the next-request of 
1.3.6.1.2.1.43.17.6.1.5.1.2, which will yield the value of the OID 
1.3.6.1.4.1.1602.1.1.1.1.0, which is the first node of a separate subtree that
snmpscrape.py didn't get previously. Now it has those OIDs, and thus can
respond to that subtree as well. This update is the first of many that will
be needed to respond to a 'find printer' call.

#50