Fix webrtcsdp.cc compilation on Android.
Fix webrtcsdp.cc compilation on Android.

Result of std::vector<>::begin() is not an lvalue and so it cannot
be incremented using ++ operator.

TBR=hellner@google.com

Review URL: https://webrtc-codereview.appspot.com/1094014

git-svn-id: 3dec5013d1058009ad43391d70f26dc8df6acd9d@283 dd674b97-3498-5ee5-1854-bdd07cd0ff33

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