esp32/sdkconfig: Shorten LWIP MSL period to 10 seconds.

Default MSL is 60 seconds.

The main purpose of this is to shorten time closed sockets spend in the
TIME_WAIT state. This is (2 * MSL) so previously 2 minutes, with this
change becomes 20 seconds.

Without this, a system which makes many short-lived TCP connections can
grow to be holding hundreds of sockets in TIME_WAIT.

Possible fix for micropython#12819

This work was funded through GitHub Sponsors.

Signed-off-by: Angus Gratton <angus@redyak.com.au>

ports/esp32/boards/sdkconfig.base

@@ -51,10 +51,11 @@ CONFIG_FREERTOS_THREAD_LOCAL_STORAGE_POINTERS=2
 CONFIG_FREERTOS_SUPPORT_STATIC_ALLOCATION=y
 CONFIG_FREERTOS_ENABLE_STATIC_TASK_CLEAN_UP=y
 
-# UDP
+# LWIP
 CONFIG_LWIP_PPP_SUPPORT=y
 CONFIG_LWIP_PPP_PAP_SUPPORT=y
 CONFIG_LWIP_PPP_CHAP_SUPPORT=y
+CONFIG_LWIP_TCP_MSL=10000
 
 # SSL
 # Use 4kiB output buffer instead of default 16kiB