Revert "convert predicted time output to decimal minutes..."

Was done to be consistent with other channels.  But the predictive
timer already handles predictive time in seconds(See gps.c:646).

This reverts commit 7acc491df974bae8ee1faa64c5a45190fd1a86c6.
Fix predictive timer value bad inputs.

Predictive timer is currently using seconds since firstGpsFix since
that is a low value (less chance of float error).  Test code was
using getUTCTime, which is unfortunately not really a usable value.