Fix compilation error: '_1' was not declared in this scope

Change-Id: I0f1f2df817a65f7d5b72c5280451346a0a011d47
diff --git a/lib/misc_utils/burst_file_sink_impl.cc b/lib/misc_utils/burst_file_sink_impl.cc
index 9990d86..ddcd583 100644
--- a/lib/misc_utils/burst_file_sink_impl.cc
+++ b/lib/misc_utils/burst_file_sink_impl.cc
@@ -48,7 +48,7 @@
               d_output_file(filename.c_str(), std::ofstream::binary)
     {
         message_port_register_in(pmt::mp("in"));
-        set_msg_handler(pmt::mp("in"), boost::bind(&burst_file_sink_impl::process_burst, this, _1));
+        set_msg_handler(pmt::mp("in"), boost::bind(&burst_file_sink_impl::process_burst, this, boost::placeholders::_1));
     }
 
     /*