Merge branch 'revert-a7dbe5ec' into 'release/v3.1'

Revert "Merge branch 'bugfix/fix_addr_changed_when_wifi_disconnect_v3.1' into 'release/v3.1'"

See merge request sdk/ESP8266_RTOS_SDK!1385

Author: donghengqaz

components/tcpip_adapter/tcpip_adapter_lwip.c

@@ -434,7 +434,8 @@ esp_err_t tcpip_adapter_up(tcpip_adapter_if_t tcpip_if)
         }
 
         /* use last obtained ip, or static ip */
-        esp_netif[tcpip_if]->flags |= NETIF_FLAG_UP;
+        netif_set_addr(esp_netif[tcpip_if], &esp_ip[tcpip_if].ip, &esp_ip[tcpip_if].netmask, &esp_ip[tcpip_if].gw);
+        netif_set_up(esp_netif[tcpip_if]);
     }
 
     tcpip_adapter_update_default_netif();
@@ -465,7 +466,9 @@ esp_err_t tcpip_adapter_down(tcpip_adapter_if_t tcpip_if)
             tcpip_adapter_reset_ip_info(tcpip_if);
         }
 
-        esp_netif[tcpip_if]->flags &= ~NETIF_FLAG_UP;
+        netif_set_addr(esp_netif[tcpip_if], IP4_ADDR_ANY4, IP4_ADDR_ANY4, IP4_ADDR_ANY4);
+        netif_set_down(esp_netif[tcpip_if]);
+        tcpip_adapter_start_ip_lost_timer(tcpip_if);
     }
 
     tcpip_adapter_update_default_netif();