Fix dygraph suffix and prefix formatting
Fix dygraph suffix and prefix formatting

A hack brought over from Chronograf 1.7. Without this, a screen tearing
bug will be visible near the y axis after updating the y axis' prefix or
suffix.

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