Add /tools/protoc_wrappers to .gitignore.

TBR=pbos

Review URL: https://webrtc-codereview.appspot.com/1444004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@3985 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/.gitignore b/.gitignore
index 359de33..c0376ec 100644
--- a/.gitignore
+++ b/.gitignore
@@ -70,6 +70,7 @@
 /tools/grit
 /tools/gritsettings
 /tools/gyp
+/tools/protoc_wrapper
 /tools/python
 /tools/valgrind
 /tools/win