scripted-diff: test: Rename send_message to send_without_ping

send_message only drops the bytes in a buffer and a sync is needed to
avoid intermittent test issues. Change the name of the method to make
this more apparent during review.

-BEGIN VERIFY SCRIPT-
 sed -i 's/send_message(/send_without_ping(/g' $( git grep -l 'send_message(' )
-END VERIFY SCRIPT-

test/functional/p2p_tx_privacy.py

@@ -39,7 +39,7 @@ class P2PTxSpy(P2PInterface):
         self.all_invs = []
 
     def on_version(self, message):
-        self.send_message(msg_wtxidrelay())
+        self.send_without_ping(msg_wtxidrelay())
 
     def on_inv(self, message):
         self.all_invs += message.inv