bsc: deterministic TC_ho_in_fail_msc_clears: wait for MGW setup

Randomly, this test issues the Clear Command so fast that the MGW has not yet
been set up, and hence the test cannot possibly see DLCX for endpoint conns
that haven't been set up at all. So, simply wait a bit before clearing.

Change-Id: Idd0b3810916efd02a499e0ac060a6a275265b8c3
1 file changed