Changed GSM_API to GRGSM_API so gr_modtool created blocks don't have to be modified
diff --git a/include/grgsm/receiver/receiver.h b/include/grgsm/receiver/receiver.h
index 25509d2..97297ca 100644
--- a/include/grgsm/receiver/receiver.h
+++ b/include/grgsm/receiver/receiver.h
@@ -38,7 +38,7 @@
      * \ingroup gsm
      *
      */
-    class GSM_API receiver : virtual public sync_block
+    class GRGSM_API receiver : virtual public sync_block
     {
      public:
       typedef boost::shared_ptr<receiver> sptr;