Stop catpuring loopback traffic

We're not as worried about performance at the moment

obfs4test

@@ -131,7 +131,7 @@ with open(bridge_lines_file) as f:
         try:
             logging.info("starting tcpdump for bridge %r" % nickname)
             try:
-                tcpdump_lo_proc = start_tcpdump(nickname, "lo")
+                #tcpdump_lo_proc = start_tcpdump(nickname, "lo")
                 tcpdump_eth0_proc = start_tcpdump(nickname, "eth0")
             except OSError as e:
                 logging.info("failed to start tcpdump, stopping snowflake probe: %s", e)

snowflaketest

@@ -113,7 +113,7 @@ for x in range(0, 10):
     try:
         logging.info("starting tcpdump for bridge %r" % nickname)
         try:
-            tcpdump_lo_proc = start_tcpdump(nickname, "lo")
+            #tcpdump_lo_proc = start_tcpdump(nickname, "lo")
             tcpdump_eth0_proc = start_tcpdump(nickname, "eth0")
         except OSError as e:
             logging.info("failed to start tcpdump, stopping snowflake probe: %s", e)