Cellular: Enable IPv6 stack property for BG96

Author: Mirela Chirica

features/cellular/framework/targets/QUECTEL/BG96/QUECTEL_BG96.cpp

@@ -57,7 +57,7 @@ static const intptr_t cellular_properties[AT_CellularBase::PROPERTY_MAX] = {
     1,  // AT_CMGF
     1,  // AT_CSDH
     1,  // PROPERTY_IPV4_STACK
-    0,  // PROPERTY_IPV6_STACK
+    1,  // PROPERTY_IPV6_STACK
     0,  // PROPERTY_IPV4V6_STACK
     1,  // PROPERTY_NON_IP_PDP_TYPE
     1,  // PROPERTY_AT_CGEREP