Retries are broken

[Apehum]

If the backend server doesn't have the PAPIProxyBridge plugin installed, formatPlaceholders will get stuck forever due to a deadlock caused by retries

You can reproduce this deadlock using the following example (using Kotlin):

import java.util.concurrent.CompletableFuture
import java.util.concurrent.TimeUnit

fun main() {
    test(3).get()
}

fun test(times: Int): CompletableFuture<Void> =
    CompletableFuture<Void>()
        .orTimeout(50L, TimeUnit.MILLISECONDS)
        .exceptionally {
            println("Test $times")
            test(times - 1).get()
        }

The easiest fix is to use exceptionallyAsync instead of exceptionally, but maybe you have better ideas on how to fix it

[WiIIiam278]

Fixed in #141