pcap_recorder: log printing pcap file name as dbg

The log message is quite long and makes it difficult to read the log
even with debug disabled.

Change-Id: I593c0ce02bf7a3a9d26cf1fcc7d523a313cb72eb
diff --git a/src/osmo_gsm_tester/pcap_recorder.py b/src/osmo_gsm_tester/pcap_recorder.py
index 398ec6c..98dea8b 100644
--- a/src/osmo_gsm_tester/pcap_recorder.py
+++ b/src/osmo_gsm_tester/pcap_recorder.py
@@ -37,7 +37,7 @@
         self.start()
 
     def start(self):
-        self.log('Recording pcap', self.run_dir, self.filters)
+        self.dbg('Recording pcap', self.run_dir, self.filters)
         dumpfile = os.path.join(os.path.abspath(self.run_dir), self.name() + ".pcap")
         self.process = process.Process(self.name(), self.run_dir,
                                        ('tcpdump', '-n',