lwip - Fixed lwip connected state after bringup with static ips

Thanks to @YixiaoLi for noting this was incorrect

Author: geky

features/FEATURE_LWIP/lwip-interface/lwip_stack.c

@@ -495,7 +495,6 @@ nsapi_error_t mbed_lwip_bringup(bool dhcp, const char *ip, const char *netmask,
         if (ret == SYS_ARCH_TIMEOUT) {
             return NSAPI_ERROR_DHCP_FAILURE;
         }
-        lwip_connected = true;
     }
 
 #if ADDR_TIMEOUT
@@ -510,6 +509,7 @@ nsapi_error_t mbed_lwip_bringup(bool dhcp, const char *ip, const char *netmask,
     add_dns_addr(&lwip_netif);
 #endif
 
+    lwip_connected = true;
     return 0;
 }