ansible: Change hostname to inventory_hostname

Due to the change caused by updated terraform script, we need to change
usage of variable `hostname` to `inventory_hostname`.

Signed-off-by: markoburcul <marko@status.im>

defaults/main.yml

@@ -39,8 +39,8 @@ geth_rpc_vhosts:
   - 'localhost'
   - '{{ geth_cont_name }}'
   - '{{ geth_rpc_extra_vhost }}'
-  - '{{ hostname }}'
-  - '{{ hostname }}.wg'
+  - '{{ inventory_hostname }}'
+  - '{{ inventory_hostname }}.wg'
   - '{{ ansible_local.wireguard.vpn_ip }}'
 # Wrapper for easier RPC usage
 geth_rpc_wrapper: '{{ geth_service_path }}/rpc.sh'