Remove multiple logging implementations.

Change-Id: I7474c29b394f37918a35bba58b2fab58a7be930f
diff --git a/y2018/vision/image_streamer.cc b/y2018/vision/image_streamer.cc
index b0c1f86..fa5f4b5 100644
--- a/y2018/vision/image_streamer.cc
+++ b/y2018/vision/image_streamer.cc
@@ -289,7 +289,7 @@
 int main(int argc, char ** argv) {
   gflags::ParseCommandLineFlags(&argc, &argv, false);
   ::aos::logging::Init();
-  ::aos::logging::AddImplementation(
+  ::aos::logging::SetImplementation(
       new ::aos::logging::StreamLogImplementation(stderr));
 
   TCPServer<MjpegDataSocket> tcp_server_(80);