package/python-esptool: fix zlib module for python3

Fixes config with BR2_PACKAGE_PYTHON3=y

WARNING: unmet direct dependencies detected for BR2_PACKAGE_PYTHON_ZLIB
  Depends on [n]: BR2_PACKAGE_PYTHON [=n]
  Selected by [y]:
  - BR2_PACKAGE_PYTHON_ESPTOOL [=y] && (BR2_PACKAGE_PYTHON [=n] || BR2_PACKAGE_PYTHON3 [=y])

Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
diff --git a/package/python-esptool/Config.in b/package/python-esptool/Config.in
index 7d3579a..570f9aa 100644
--- a/package/python-esptool/Config.in
+++ b/package/python-esptool/Config.in
@@ -3,7 +3,8 @@
 	select BR2_PACKAGE_PYTHON_ECDSA # runtime
 	select BR2_PACKAGE_PYTHON_PYAES # runtime
 	select BR2_PACKAGE_PYTHON_SERIAL # runtime
-	select BR2_PACKAGE_PYTHON_ZLIB # runtime
+	select BR2_PACKAGE_PYTHON_ZLIB if BR2_PACKAGE_PYTHON
+	select BR2_PACKAGE_PYTHON3_ZLIB if BR2_PACKAGE_PYTHON3
 	help
 	  A serial utility to communicate & flash code to Espressif
 	  ESP8266 & ESP32 chips.