Document proxy.config.hostdb.lookup_timeout
Document proxy.config.hostdb.lookup_timeout

test: https://git-wip-us.apache.org/repos/asf?p=trafficserver.git;a=commit;h=ee87aecbd08abaac4b5fa7b50ac120fdf17553c2

reveller/trafficserver,chenglongwei/trafficserver,PSUdaemon/trafficserver,PSUdaemon/trafficserver,chenglongwei/trafficserver,rahmalik/trafficserver,SolidWallOfCode/trafficserver,rpufky/trafficserver,SolidWallOfCode/trafficserver,chitianhao/trafficserver,rahmalik/trafficserver,clearswift/trafficserver,bryancall/trafficserver,rpufky/trafficserver,vmamidi/trafficserver,rahmalik/trafficserver,clearswift/trafficserver,vmamidi/trafficserver,rahmalik/trafficserver,clearswift/trafficserver,duke8253/trafficserver,dyrock/trafficserver,reveller/trafficserver,SolidWallOfCode/trafficserver,taoyunxing/trafficserver,rpufky/trafficserver,chenglongwei/trafficserver,davidbz/trafficserver,reveller/trafficserver,taoyunxing/trafficserver,PSUdaemon/trafficserver,SolidWallOfCode/trafficserver,clearswift/trafficserver,vmamidi/trafficserver,dyrock/trafficserver,taoyunxing/trafficserver,persiaAziz/trafficserver,duke8253/trafficserver,pbchou/trafficserver,pbchou/trafficserver,rpufky/trafficserver,clearswift/trafficserver,bryancall/trafficserver,taoyunxing/trafficserver,persiaAziz/trafficserver,PSUdaemon/trafficserver,chitianhao/trafficserver,chitianhao/trafficserver,chitianhao/trafficserver,bryancall/trafficserver,davidbz/trafficserver,davidbz/trafficserver,taoyunxing/trafficserver,taoyunxing/trafficserver,pbchou/trafficserver,persiaAziz/trafficserver,vmamidi/trafficserver,davidbz/trafficserver,reveller/trafficserver,SolidWallOfCode/trafficserver,reveller/trafficserver,rpufky/trafficserver,taoyunxing/trafficserver,persiaAziz/trafficserver,dyrock/trafficserver,bryancall/trafficserver,rahmalik/trafficserver,reveller/trafficserver,clearswift/trafficserver,taoyunxing/trafficserver,PSUdaemon/trafficserver,chenglongwei/trafficserver,reveller/trafficserver,PSUdaemon/trafficserver,reveller/trafficserver,dyrock/trafficserver,PSUdaemon/trafficserver,duke8253/trafficserver,PSUdaemon/trafficserver,rpufky/trafficserver,persiaAziz/trafficserver,chitianhao/trafficserver,rahmalik/trafficserver,chenglongwei/trafficserver,chitianhao/trafficserver,duke8253/trafficserver,PSUdaemon/trafficserver,SolidWallOfCode/trafficserver,bryancall/trafficserver,chenglongwei/trafficserver,SolidWallOfCode/trafficserver,bryancall/trafficserver,chenglongwei/trafficserver,persiaAziz/trafficserver,davidbz/trafficserver,persiaAziz/trafficserver,rpufky/trafficserver,pbchou/trafficserver,dyrock/trafficserver,rahmalik/trafficserver,davidbz/trafficserver,pbchou/trafficserver,pbchou/trafficserver,duke8253/trafficserver,vmamidi/trafficserver,taoyunxing/trafficserver,duke8253/trafficserver,chenglongwei/trafficserver,duke8253/trafficserver,vmamidi/trafficserver,clearswift/trafficserver,rpufky/trafficserver,rahmalik/trafficserver,clearswift/trafficserver,dyrock/trafficserver,chitianhao/trafficserver,dyrock/trafficserver,rahmalik/trafficserver,rpufky/trafficserver,persiaAziz/trafficserver,clearswift/trafficserver,reveller/trafficserver