check if targetClient is undefined (#1110)
check if targetClient is undefined (#1110)


jcague/licode,lynckia/licode,lynckia/licode,jcague/licode,lynckia/licode,yangjinecho/licode,MModal/licode,MModal/licode,yangjinecho/licode,lynckia/licode,jcague/licode,lodoyun/licode,lynckia/licode,MModal/licode,yangjinecho/licode,jcague/licode,lodoyun/licode,MModal/licode,lynckia/licode,yangjinecho/licode,yangjinecho/licode,MModal/licode,MModal/licode,yangjinecho/licode,lodoyun/licode,lodoyun/licode,jcague/licode,yangjinecho/licode,lodoyun/licode,jcague/licode,lynckia/licode,MModal/licode,lodoyun/licode,jcague/licode,yangjinecho/licode,lodoyun/licode