[Halld-offline] [EXTERNAL] Fix for recent raw data runs

[Sean Dobbs]

Hi all,

Just to follow up on one of the recent crashes, the ones reported in
this log entry: https://logbooks.jlab.org/entry/3755376
seem to be due to f250 raw mode pulses that don't have any raw data attached.

I just pushed a pull request to properly report and skip over this error.

For those interested in looking in more detail at one of these pulses,
you can look at run 71137, event 43, rocid/slot/channel 13/13/12.

More details are in this log entry: https://logbooks.jlab.org/entry/3756335

Cheers,
Sean