junos doesn't put usable vlan ids in most of Q-BRIDGE-MIB, translation in fdb-table

Where objects in Q-BRIDGE-MIB are organized by vlan, JUNOS puts consecutive numbers in place of the actual vlan id. The attached patch translates those numbers for the fdb-table poller to the previously discovered actual vlan id from JUNIPER-VLAN-MIB, so that mac addresses found on the switch have the correct related vlan in the vlans_fdb mysql table.