reduce numeric precision in Gateways Widget
Currently the v2.3.x Gateways Widget is displaying 3 digits after the decimal point for the gateway RTT & RTTsd values (e.g. 12.345ms). This could be reduced to 1 digit (e.g. 12.3ms) with no loss in meaningful accuracy for latency values. An added bonus is that this would improve the Gateways Widget display in 3 column dashboards.