Bad SCREEN line causes high rate polling

[ryanmelt]

A telemetry SCREEN line like this:

SCREEN "A description" Auto Auto 1.0

Causes rapid polling in telemetry viewer with no errors displayed.
Note that the SCREEN line doesn't take a description parameters as the first argument.

This should throw an error and not cause rapid polling (Most likely Auto is turning into NaN, and then somehow causing no delay between polls).

[clayandgen]

Would be good to add validation to the refresh interval to Bucket Explorer + Tlm Viewer, similar to that of System Health Tool