Remove recommendation to include clock correction in NOT CLOCK CORRECTED data

The miniSEED section of the current standards document states, for NOT CLOCK CORRECTED data:
"Put time correction in record header field 16 and set field 12 bit 1 to 0"

I propose changing this to:
"Set RH field 12 bit 1 to 0"

As I don't think that NOT CLOCK CORRECTED data should be required to indicate the calculated clock correction (nor should it be required not to).