Bluetooth: Mesh: Fix incorrect write conn_count
Bluetooth: Mesh: Fix incorrect write conn_count

When Device use pb-gatt bearer provisioning, and first
provisioning failed due to some reasons(invalid oob etc..).

Which cause `proxy:gatt_disconnectd` incorrected write `conn_count`

Cause this var euqals `-1`.

Signed-off-by: Lingao Meng <d107961e9e4fef34975d9e927886461599dc7eda@xiaomi.com>

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