fix compilation and linking on Mac OS X
diff --git a/lib/qa_utils/burst_sink_impl.cc b/lib/qa_utils/burst_sink_impl.cc
index de26d39..5f1ae64 100644
--- a/lib/qa_utils/burst_sink_impl.cc
+++ b/lib/qa_utils/burst_sink_impl.cc
@@ -28,6 +28,7 @@
 #include "burst_sink_impl.h"
 #include <stdio.h>
 #include <sstream>
+#include <grgsm/endian.h>
 #include <grgsm/gsmtap.h>
 
 namespace gr {