[evlatests] S band default frequencies

[Ken Sowinski]

The satellite radio signals at 2300 MHz are strong ebough in LCP to
seriously distort the attenuator settings in the down converters such
that power as seen at the VLA T5s is much too low.  To avoid this
I suggest moving the default S band frequencies for use with the
old correlator from 3000 and 3050 MHz to 3500 and 3550 MHz.  This
will move 2300 MHz out of the downconverter input filter bandpass.

I can change the default frequencies in the parameters DB, but does
anything else (such as obs2script) need to be changed as well?