Changed GSM_API to GRGSM_API so gr_modtool created blocks don't have to be modified
diff --git a/include/grgsm/misc_utils/message_file_source.h b/include/grgsm/misc_utils/message_file_source.h
index 51d2525..2ad61f9 100644
--- a/include/grgsm/misc_utils/message_file_source.h
+++ b/include/grgsm/misc_utils/message_file_source.h
@@ -34,7 +34,7 @@
      * \ingroup gsm
      *
      */
-    class GSM_API message_file_source : virtual public gr::block
+    class GRGSM_API message_file_source : virtual public gr::block
     {
      public:
       typedef boost::shared_ptr<message_file_source> sptr;