l2vpn: fix bug in app links generation
l2vpn: fix bug in app links generation

The PW-facing links of the dispatcher apps need to be qualified by the
name of the VPLS because the PW names are only unique within a VPLS.

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