Method setOnce

SIP/SIPUtility.h:154–156

Set the timer but only if it is not already running.

	} 
	// Set the timer but only if it is not already running.
	void setOnce(long wLimitTime) {
		if (!mActive) set(wLimitTime);
	}
	// Double the timer value but no more than maxTime.  Lots of UDP connection timers in SIP use this.
	void setDouble(unsigned maxTime=10000) {
		assert(mLimitTime!=0);