fix decimal in snr value in rangetest.csv

app/src/main/java/com/geeksville/mesh/model/UIState.kt

@@ -607,7 +607,7 @@ class UIViewModel @Inject constructor(
                             val rxLat = rxPos?.latitude ?: ""
                             val rxLong = rxPos?.longitude ?: ""
                             val rxAlt = rxPos?.altitude ?: ""
-                            val rxSnr = "%f".format(proto.rxSnr)
+                            val rxSnr = "%f".format(proto.rxSnr, Locale.US)
 
                             // Calculate the distance if both positions are valid