SpikeGadgetsRawIO Gives incorrect channel ids with recording missing hardware channels

[pauladkisson]

SpikeGadgetsRawIO incorrectly assigns channel ids when the recording is missing some hardware channels but the total number of channels is still an integer multiple of n_channel_per_chip (32). In this case, I have a recording with 256 hardware channels, but 32 are missing (so 224 actual recorded channels of data). I have worked out that in this case, spikegadgets just skips the missing channels and continues with its pattern. For example, hwChan 64 is missing, so the first few channels are (0, 32, 96, ...).