Remove unused variable

Fixup for I489460cd4919907516e504e6694d7cef544b0da6.

Change-Id: Ia0c05e23e03152b75e3dc4c6e2011f2339e2dcfc
diff --git a/aos/network/message_bridge_server_lib.h b/aos/network/message_bridge_server_lib.h
index 2a75ad6..c0c1d56 100644
--- a/aos/network/message_bridge_server_lib.h
+++ b/aos/network/message_bridge_server_lib.h
@@ -91,8 +91,6 @@
   const int channel_index_;
   const Channel *const channel_;
 
-  std::unique_ptr<aos::RawFetcher> fetcher_;
-
   std::vector<Peer> peers_;
 
   std::deque<SizePrefixedFlatbufferDetachedBuffer<logger::MessageHeader>>