fix .server_state()attribute name

```
...
socket.set_interface(esp)
ss = socket.socket()
esp.start_server(PORT, ss.socknum)
print("Server status: ", esp.server_state(ss.socknum))
print("Server status: ", esp.get_server_state(ss.socknum))
```
yields
```
Server status:  1
Traceback (most recent call last):
  File "code.py", line 76, in <module>
AttributeError: 'ESP_SPIcontrol' object has no attribute 'get_server_state'
```

Author: anecdata

adafruit_esp32spi/adafruit_esp32spi_wsgiserver.py

@@ -75,7 +75,7 @@ def start(self):
             print("Server available at {0}:{1}".format(ip, self.port))
             print(
                 "Sever status: ",
-                _the_interface.get_server_state(self._server_sock.socknum),
+                _the_interface.server_state(self._server_sock.socknum),
             )
 
     def update_poll(self):