Reduce announcement logging text.

Author: evoskuil

src/protocols/protocol_header_out_70012.cpp

@@ -112,7 +112,8 @@ bool protocol_header_out_70012::do_announce(header_t link) NOEXCEPT
         return true;
     }
 
-    LOGN("Announce " << encode_hash(hash) << " to [" << opposite() << "].");
+    LOGN("Announce ..." << encode_hash(hash).substr(hash_size - 8, 8)
+        << " to [" << opposite() << "].");
     SEND(headers{ { ptr } }, handle_send, _1);
     return true;
 }