Method acquire

app/src/main/java/eu/faircode/email/Core.java:5855–5862

(long milliseconds, boolean backingoff)

        }

        boolean acquire(long milliseconds, boolean backingoff) throws InterruptedException {
            try {
                this.backingoff = backingoff;
                return semaphore.tryAcquire(milliseconds, TimeUnit.MILLISECONDS);
            } finally {
                this.backingoff = false;
            }
        }

        void error(Throwable ex) {
            if (ex instanceof MessagingException &&