testutils/httputils: don't print the serve message before listening
testutils/httputils: don't print the serve message before listening

Since the tests that use the inspect binary rely on stdout parsing,
printing this too early will cause a race condition between the serve
and test code. Simply moving the print to a point after the Listen()
call prevents that.

jjlakis/rkt,euank/rkt,mike1729/rkt,lucasallan/rkt,achanda/rkt,sgotti/rkt,shobhit85/rkt,ybubnov/rkt,matthaias/rkt,monstermunchkin/rkt,joshix/rkt,alban/rkt,linki/rkt,joshix/rkt,il9ue/rkt,rkt/rkt,achanda/rkt,jasonchaffee/rkt,il9ue/rkt,tmrts/rkt,cab105/rkt,joshix/rkt,mike1729/rkt,sinfomicien/rkt,s-urbaniak/rkt,shobhit85/rkt,liugenping/rkt,jonboulle/rkt,yifan-gu/rocket,alban/rkt,ybubnov/rkt,intelsdi-x/rkt,tmrts/rkt,nhlfr/rkt,krnowak/rkt,adfernandes/rkt,blixtra/rkt,blixtra/rkt,jakon89/rkt,dgonyeo/rkt,coreos/rkt,s-urbaniak/rkt,intelsdi-x/rkt,rkt/rkt,adfernandes/rkt,yifan-gu/rocket,endocode/rkt,yifan-gu/rkt,Shashwatsh/rkt,il9ue/rkt,jakon89/rkt,rkt/rkt,cab105/rkt,jasonchaffee/rkt,kinvolk/rkt,Wilybald/rkt,liugenping/rkt,yifan-gu/rkt,euank/rkt,sgotti/rkt,sstabellini/rkt,markllama/rkt,akshaykarle/rkt,akshaykarle/rkt,joshix/rkt,liugenping/rkt,jjlakis/rkt,kinvolk/rkt,jzelinskie/rkt,alban/rkt,endocode/rkt,coreos/rkt,lucasallan/rkt,yifan-gu/rkt,coreos/rkt,linki/rkt,kbrwn/rkt,Wilybald/rkt,markllama/rkt,lucasallan/rkt,kinvolk/rkt,lucasallan/rkt,tmrts/rkt,yifan-gu/rocket,dgonyeo/rkt,matthaias/rkt,s-urbaniak/rkt,sstabellini/rkt,shobhit85/rkt,squeed/rkt,endocode/rkt,linki/rkt,kbrwn/rkt,jonboulle/rkt,kbrwn/rkt,kinvolk/rkt,nhlfr/rkt,ybubnov/rkt,squeed/rkt,krnowak/rkt,matthaias/rkt,cab105/rkt,sstabellini/rkt,sgotti/rkt,achanda/rkt,rkt/rkt,jjlakis/rkt,jakon89/rkt,jasonchaffee/rkt,Wilybald/rkt,intelsdi-x/rkt,monstermunchkin/rkt,jzelinskie/rkt,krnowak/rkt,dgonyeo/rkt,nhlfr/rkt,blixtra/rkt,sinfomicien/rkt,monstermunchkin/rkt,Shashwatsh/rkt,Wilybald/rkt,squeed/rkt,sinfomicien/rkt,markllama/rkt,mike1729/rkt,akshaykarle/rkt,euank/rkt,Shashwatsh/rkt,adfernandes/rkt,jonboulle/rkt,jzelinskie/rkt