StringToNumber bug in 2.0.7

Started playing with Device Extensions' Conversion Extension and tried to convert string to number and bumped into this error in Indigo:

`   EPS - Device Extensions Error   Exception in plugin._stringToNumber line 3496: global name 'pprops' is not defined
							 CODE: if ext.valueValid (pprops, "trimstart", True)`

I guess "pprops" should be "props" as I briefly looked at the code.