wifi: shell: Add missing bracket
wifi: shell: Add missing bracket

This fixes the output below by adding the missing closing bracket to
"<MFP (optional): 0:Disable, 1:Optional, 2:Required":

Fixes:

	uart:~$ wifi
	wifi - Wi-Fi commands
	Subcommands:
	  connect     :Connect to a Wi-Fi AP
	               "<SSID>"
	               <channel number (optional), 0 means all>
	               <PSK (optional: valid only for secure SSIDs)>
	               <Security type (optional: valid only for secure SSIDs)>
	               0:None, 1:PSK, 2:PSK-256, 3:SAE
	               <MFP (optional): 0:Disable, 1:Optional, 2:Required
	               ^-------------------------------------------------^
	               (...)

Signed-off-by: Gaël PORTAY <1666f60cfa201a60b0ea694168a0b6932673170a@gmail.com>

zephyrproject-rtos/zephyr,finikorg/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,galak/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,finikorg/zephyr,finikorg/zephyr,galak/zephyr,galak/zephyr,zephyrproject-rtos/zephyr