Bluetooth: GATT: Fix crash when using CONFIG_BT_CONN_DISABLE_SECURITY
Bluetooth: GATT: Fix crash when using CONFIG_BT_CONN_DISABLE_SECURITY

When using CONFIG_BT_CONN_DISABLE_SECURITY bt_gatt_check_perm would
ignore not only the security sensitive permissions but also access
related ones causing crashes since the callback would be NULL.

Signed-off-by: Luiz Augusto von Dentz <8530c5ea66a1bdbc08f98bfcf183c8be901b5990@intel.com>

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