JBM decoder assert

When running the decoder in JBM and the DEBUGGING switch is activated, the short self-test reports 5 run errors:

• Multi-channel 7_1 bitrate switching, 48kHz in, 32kHz out, BINAURAL_ROOM_REVERB out, HR, JBM Prof 5 (Decoding)
• Multi-channel 7_1_4 bitrate switching, 48kHz in, 48kHz out, BINAURAL out, HR, JBM Prof 5 (Decoding)
• OMASA 1Dir1TC 4ISM at br sw techs 13.2 to 512 kbps start 32 kbps, 48kHz in, 48kHz out, BINAURAL out, JBM Prof 5 (Decoding)
• 3 ISM with metadata bitrate switching from 48 kbps to 32 kbps, 48 kHz in, 32 kHz out, DTX, BINAURAL_ROOM_IR out, JBM Prof 5 (Decoding)
• 4 ISM with metadata bitrate switching from 48 kbps to 32 kbps, 48 kHz in, 48 kHz out, BINAURAL out, object editing, JBM Prof 5 (Decoding)

When looking at the last one, it hits the assert in the function ivas_jbm_dec_tc_buffer_reconfigure():

    assert( hTcBuffer->subframe_nbslots[hTcBuffer->subframes_rendered - 1] == nMaxSlotsPerSubframeOld );