Fix clang warning in stun.cc
Fix clang warning in stun.cc

TBR=juberti@google.com

Review URL: https://webrtc-codereview.appspot.com/536002

git-svn-id: 3dec5013d1058009ad43391d70f26dc8df6acd9d@136 dd674b97-3498-5ee5-1854-bdd07cd0ff33

princeofdarkness76/swtoolkit,xhook/libjingle,iamnpc/libjingle,shiquxinkong/jingle,xhook/libjingle,vigsterkr/libjingle,deepak899/libjingle,volkanh/libjingle,jgrowl/libjingle,iamnpc/libjingle,volkanh/libjingle,iamnpc/libjingle,wangscript/libjingle-1,wangscript/libjingle,MindsIgnited/libjingle,shiquxinkong/jingle,deepak899/libjingle,wangscript/libjingle-1,shiquxinkong/jingle,bitemyapp/libjingle,goddino/libjingle,lukeweber/libjingle-override,xhook/libjingle,bitemyapp/libjingle,volkanh/libjingle,goddino/libjingle,shiquxinkong/jingle,lukeweber/libjingle-override,wangscript/libjingle-1,wangscript/libjingle,wangscript/libjingle,vigsterkr/libjingle,volkanh/libjingle,jgrowl/libjingle,volkanh/libjingle,goddino/libjingle,jgrowl/libjingle,vigsterkr/libjingle,wangscript/libjingle-1,wangscript/libjingle,jgrowl/libjingle,bitemyapp/libjingle,bitemyapp/libjingle,bitemyapp/libjingle,deepak899/libjingle,vigsterkr/libjingle,shiquxinkong/jingle,princeofdarkness76/swtoolkit,iamnpc/libjingle,xhook/libjingle,lukeweber/libjingle-override,wangscript/libjingle,princeofdarkness76/swtoolkit,princeofdarkness76/swtoolkit,goddino/libjingle,MindsIgnited/libjingle,wangscript/libjingle-1,lukeweber/libjingle-override,princeofdarkness76/swtoolkit,jgrowl/libjingle,shiquxinkong/jingle,bitemyapp/libjingle,MindsIgnited/libjingle,xhook/libjingle,volkanh/libjingle,deepak899/libjingle,iamnpc/libjingle,iamnpc/libjingle,goddino/libjingle,lukeweber/libjingle-override,wangscript/libjingle,princeofdarkness76/swtoolkit,deepak899/libjingle,wangscript/libjingle-1,vigsterkr/libjingle,wangscript/libjingle-1,deepak899/libjingle