all temperature should be in celsius

soil temperature in CF is in K, capful assumes it is in C.

@ankurdesai @mdietze @jam2767 this fixes the gapfilling for soil temperatures..
```r
EddyData.F['Tair'] <- ud.convert(EddyData.F['Tair'], "Kelvin", "Celsius")
EddyData.F['Ts1'] <- ud.convert(EddyData.F['Ts1'], "Kelvin", "Celsius")
```