Update the header_rewrite doc for clarification on CLIENT-URL:HOST
Update the header_rewrite doc for clarification on CLIENT-URL:HOST

dyrock/trafficserver,bryancall/trafficserver,davidbz/trafficserver,vmamidi/trafficserver,pbchou/trafficserver,duke8253/trafficserver,duke8253/trafficserver,davidbz/trafficserver,bryancall/trafficserver,bryancall/trafficserver,bryancall/trafficserver,SolidWallOfCode/trafficserver,SolidWallOfCode/trafficserver,dyrock/trafficserver,duke8253/trafficserver,chitianhao/trafficserver,vmamidi/trafficserver,dyrock/trafficserver,SolidWallOfCode/trafficserver,chitianhao/trafficserver,davidbz/trafficserver,bryancall/trafficserver,vmamidi/trafficserver,vmamidi/trafficserver,dyrock/trafficserver,davidbz/trafficserver,vmamidi/trafficserver,pbchou/trafficserver,SolidWallOfCode/trafficserver,bryancall/trafficserver,chitianhao/trafficserver,dyrock/trafficserver,pbchou/trafficserver,chitianhao/trafficserver,vmamidi/trafficserver,SolidWallOfCode/trafficserver,dyrock/trafficserver,duke8253/trafficserver,pbchou/trafficserver,pbchou/trafficserver,chitianhao/trafficserver,pbchou/trafficserver,davidbz/trafficserver,SolidWallOfCode/trafficserver,dyrock/trafficserver,davidbz/trafficserver,duke8253/trafficserver,duke8253/trafficserver,chitianhao/trafficserver,SolidWallOfCode/trafficserver,chitianhao/trafficserver,duke8253/trafficserver