BSSAP_LE_Emulation: Increase timeout in f_bssap_le_wait_sccp_peer_available()
It was spotted in SMLC_Tests.ttcn that the current timeout may be too short, and the test fails because ttcn3 connects to STP and receives a DUNA, and then the IUT (osmo-smlc) connects to STP around 4 seconds later, which is too late with existing timeout.
