Add null guard to tag parsing function to prevent parsing values that don't match tag RegEx.
Add null guard to tag parsing function to prevent parsing values that don't match tag RegEx.

mark-rushakoff/influxdb,nooproblem/influxdb,li-ang/influxdb,influxdb/influxdb,nooproblem/influxdb,mark-rushakoff/influxdb,influxdb/influxdb,influxdata/influxdb,li-ang/influxdb,influxdb/influxdb,influxdb/influxdb,influxdb/influxdb,influxdata/influxdb,mark-rushakoff/influxdb,mark-rushakoff/influxdb,nooproblem/influxdb,nooproblem/influxdb,influxdb/influxdb,nooproblem/influxdb,mark-rushakoff/influxdb,mark-rushakoff/influxdb