disable metadata in pu tx example

examples/pu_tx_1_channel.grc

@@ -219,7 +219,7 @@ blocks:
     in_clk: ONBOARD
     lpf_mode: disabled
     maxoutbuf: '0'
-    metadata: 'True'
+    metadata: 'False'
     minoutbuf: '0'
     nchan: '1'
     out_clk: 'False'
@@ -235,7 +235,7 @@ blocks:
     trigger_role1: master
     trigger_signal0: J51_1
     trigger_signal1: J51_1
-    tsb_tag_name: packet_len
+    tsb_tag_name: ''
     use_dac: 'False'
     verbosity: warning
     xb200: none