OPENTHREAD_CONFIG_SRP_CLIENT_RETRY_WAIT_INTERVAL_JITTER macro

@def OPENTHREAD_CONFIG_SRP_CLIENT_RETRY_WAIT_INTERVAL_JITTER Specifies jitter (in msec) for retry wait interval. If the current retry wait interval is smaller than the jitter then the wait interval itself is used as jitter (e.g., with jitter 500 msec and if retry interval is 300ms the retry interval is then randomly selected from [0, 2*300] ms).