Crashlytics reporting a crash when the user lost the internet connection

Hi everyone,

When the `enableAnalytics` is enabled if the user had the app opened but out of the sudden lost the internet connection, the syncing method will throw an error that is not caught anywhere and thus reports a crash.

I believe that we should not throw the error and instead just log it. What do you think about it?

In the meantime, I'll disable the analytics to avoid any crashes.

https://github.com/Flagsmith/flagsmith-flutter-client/blob/284bab1dadf54e0782c89f3b1fa43a5c27e67fd1/lib/src/flagsmith_client.dart#L95

Start at lib/src/flagsmith_client.dart around line 95, where the analytics syncing method is linked, and reproduce the behavior with the app offline. Done means losing connectivity while analytics is enabled no longer reports a crash and the error is logged instead.

Written by the indexing model from the issue text.