grc/gsm_block_tree: add forgotten gsm_trx_burst_if block
diff --git a/grc/gsm_block_tree.xml b/grc/gsm_block_tree.xml
index ae41f4d..479bdb4 100644
--- a/grc/gsm_block_tree.xml
+++ b/grc/gsm_block_tree.xml
@@ -71,6 +71,7 @@
       <block>gsm_clock_offset_corrector_tagged</block>
       <block>gsm_msg_to_tag.xml</block>
       <block>gsm_tmsi_dumper</block>
+      <block>gsm_trx_burst_if</block>
     </cat>
   </cat>
 </cat>