Update suggested versions and manually merge connection error check

[kotl]

No description provided.

[proppy]

Thanks for doing this.

This should help us with the following issues:
#354
#355
#349
#301

[anhthoai]

Firebase.stream() is still not working well. Firebase.failed() happens only after some time you don't interact on firebase.
I have tested when putting Firebase.stream() in loop() also. It still has problem.

[am-canes]

@anhthoai I am having the same problem.

[MrSuhov]

I am having this issue. I found out that the stream looses its connection right after my modem switches between 3G and LTE.
Are there any workarounds to get the status of the stream connection and how a re-connection should be made? Calling Firebase.stream() in the loop does not re-establish stream connection resulting in an endless Firebase.failed() with empty error Firebase.error().

SDK:2.2.1(cfd48f3)/Core:win-2.5.0-dev/lwIP:2.0.3(STABLE-2_0_3_RELEASE/glue:arduino-2.4.1-10-g0c0d8c2)/BearSSL:94e9704

[kotl]

I've been fighting to figure out how we can report error from losing connection, however current implementation of WifiClientSecure in the Arduino Core 2.4.1 is incapable of doing so. There are no workaround at the moment except you will probably have to reboot your MC. Fix for empty error() is coming, however that won't fix the underlying problem here:
https://github.com/esp8266/Arduino/blob/2.4.1/libraries/ESP8266WiFi/src/WiFiClientSecure.cpp#L377
that connection state changes are not propagated to higher levels of abstraction.

We had this problem before, it's not new. Recent changes in Arduino Core suggest we will have options in the future. However, I probably won't do anything until next official release or RC is made. (2.4.2, I guess).