samples: cellular: lte_ble_gateway: Add IPv4 support to LTE BLE gateway

Add CONFIG_NET_IPV4=y to prj.conf to support IPv4 in the LTE BLE gateway
sample.

Signed-off-by: Einar Thorsrud <einar.thorsrud@nordicsemi.no>

Author: einarthorsrud

samples/cellular/lte_ble_gateway/prj.conf

@@ -12,6 +12,7 @@ CONFIG_NETWORKING=y
 CONFIG_NET_NATIVE=n
 CONFIG_NET_SOCKETS=y
 CONFIG_NET_SOCKETS_OFFLOAD=y
+CONFIG_NET_IPV4=y
 
 # LTE link control
 CONFIG_LTE_LINK_CONTROL=y