Changes

src/rspro_client_fsm: fix osmo_stream_cli_destroy

Fix for:
  Assert failed stream_cli_close(cli) == false ../../src_copy/libosmo-netif/src/stream_cli.c:1023

Reproducer in osmo-ttcn3-hacks:
  ./testenv.py run remsim -c client -t RemsimClient_Tests.TC_bank_disconnect

Suggested-by: Pau Espin Pedrol <pespin@sysmocom.de>
Change-Id: I0da0b4354532b4e13d0c4bf4b132ec774f24497f