Fixed CHANNEL in ESPNow example

[PilnyTomas]

Description of Change

ESPNow example could not work properly because of the unaligned CHANNEL hardcoded in the example.
This simple fix set them both in Master and Slave to 1.

Tests scenarios

Master on ESP32 DevKit with WROOM-32D
Slave on DevKit with WROWER-B
Arduino-ESP32 core version 2.0.4
Arduino IDE version 1.8.19

Master's serial output:

Found 5 devices 
Found a Slave.
1: Slave_1 [xx:xx:xx:xx:xx:xx] (-27)
Slave Found, processing..
Slave Status: Pair success
Sending: 1
Send Status: Success
Last Packet Sent to: xx:xx:xx:xx:xx:xx
Last Packet Send Status: Delivery Success

Found 4 devices 
Found a Slave.
1: Slave_1 [xx:xx:xx:xx:xx:xx] (-25)
Slave Found, processing..
Slave Status: Already Paired
Sending: 2
Send Status: Success
Last Packet Sent to: xx:xx:xx:xx:xx:xx
Last Packet Send Status: Delivery Success

Slave's serial output:

ESPNow Init Success
Last Packet Recv from: xx:xx:xx:xx:xx:xx
Last Packet Recv Data: 1

Last Packet Recv from: xx:xx:xx:xx:xx:xx
Last Packet Recv Data: 2

Related links

Related to #2653 but NOT solving the main problem - could not replicate.

[P-R-O-C-H-Y]

LGTM!