delete_head_blocking replacement for 3.8

Dear All,

What is the proper replacement code for the delete_head_blocking
function that was removed in gnuradio 3.8? I see that in
pdu_to_tagged_stream simply using delete_head_nowait is used with
checking for NULL and returning 0 in the work function. Will the block
scheduler run this code in a busy loop?

Best,
Miklos