Workaround for espressif/arduino-esp32#2685

Newer plattform has support for saving configuration, older need older 
async-tcp.

Author: Johannes Formann

Diff for: platformio.ini

@@ -9,11 +9,11 @@
 ; https://docs.platformio.org/page/projectconf.html
 
 [env:featheresp32]
-platform = espressif32@1.9.0
+platform = espressif32@1.7.0
 board = featheresp32
 framework = arduino
 board_build.partitions = no_ota_eeprom.csv
 build_flags = -DNO_GLOBAL_EEPROM -DDEBUG_EEPROM32_ROTATE_PORT=Serial -DI2C_BUFFER_LENGTH=255 -g
 ;-DUSE_SERIAL
-lib_deps = AsyncTCP, Adafruit Unified Sensor, ESP32CAN, Adafruit FXOS8700, Adafruit FXAS21002C, Adafruit AHRS, SparkFun LSM9DS1 IMU
+lib_deps = AsyncTCP@1.0.3, Adafruit Unified Sensor, ESP32CAN, Adafruit FXOS8700, Adafruit FXAS21002C, Adafruit AHRS, SparkFun LSM9DS1 IMU
 upload_port = /dev/ttyUSB1