connectx4.lua: minor changes
connectx4.lua: minor changes

Fix the opcode for DISABLE_HCA (currently unused), add assert to
alloc_pages() method.

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