[UKF] Change Royal Engineer Recovery Squad to Passive Upgrade

addvaluej…

I think this case is different from T34/T34-85 or M4/M4E8, because the original version of T34 or M4 takes less population cap and less resource, so player may choose to build original version some times.

However, Royal Engineer Recovery Squad takes same population cap as the original version, the price between it and its original version is so small that I didn't see any reason to build the original version.

I suggest to change Royal Engineer Recovery Squad to Passive Upgrade.