"snabb config" tests wait until ptree manager socket is available
"snabb config" tests wait until ptree manager socket is available

This replaces "sleep" calls with deterministic waits.

dpino/snabbswitch,Igalia/snabb,eugeneia/snabb,SnabbCo/snabbswitch,Igalia/snabb,eugeneia/snabb,dpino/snabb,snabbco/snabb,snabbco/snabb,snabbco/snabb,eugeneia/snabb,Igalia/snabbswitch,dpino/snabb,Igalia/snabbswitch,Igalia/snabbswitch,eugeneia/snabbswitch,Igalia/snabb,alexandergall/snabbswitch,eugeneia/snabbswitch,alexandergall/snabbswitch,SnabbCo/snabbswitch,dpino/snabbswitch,dpino/snabbswitch,eugeneia/snabb,alexandergall/snabbswitch,snabbco/snabb,SnabbCo/snabbswitch,Igalia/snabb,alexandergall/snabbswitch,SnabbCo/snabbswitch,Igalia/snabb,eugeneia/snabbswitch,eugeneia/snabbswitch,snabbco/snabb,Igalia/snabb,eugeneia/snabb,dpino/snabbswitch,Igalia/snabbswitch,alexandergall/snabbswitch,snabbco/snabb,dpino/snabb,alexandergall/snabbswitch,eugeneia/snabb,dpino/snabb,alexandergall/snabbswitch,eugeneia/snabb,Igalia/snabb,snabbco/snabb,dpino/snabb,eugeneia/snabb,Igalia/snabbswitch,alexandergall/snabbswitch,dpino/snabb,snabbco/snabb,dpino/snabb,Igalia/snabb