Added gmsk modulator block for gsm
diff --git a/grc/gsm_block_tree.xml b/grc/gsm_block_tree.xml
index 0ceec47..ac3670e 100644
--- a/grc/gsm_block_tree.xml
+++ b/grc/gsm_block_tree.xml
@@ -24,6 +24,7 @@
     <cat>
       <name>Transmitter</name>
       <block>gsm_txtime_bursts_tagger</block>
+      <block>gsm_gmsk_mod</block>
     </cat>
     <cat>
       <name>Logical channels demapping</name>