Add check for when no valid headstage ID is found

[bparks13]

Add check at this line for when hubs are being discovered:

onix-source/Source/OnixSource.cpp

Line 403 in 550b7b2

}

Add check at this line for when passthrough is selected:

onix-source/Source/OnixSource.cpp

Line 486 in 550b7b2

}

The final else should indicate that nothing was found, print out any relevant information (such as the ID that was read), and then exit cleanly.