Putting more code in a constructor is almost never advised. I would expect that whatever connection the Facebook SDK is making is not a blocker for application launch. (If you have more insight on why this code must unconditionally run this early, I would be glad to hear it.)

The gain from trying to eke out a millisecond by executing network or filesystem I/O code before main() is extremely marginal compared to the can of worms opened by doing that.

Running code before main has nothing to do with performance.