Remove date from tcpdump example.

pages/common/tcpdump.md

@@ -22,7 +22,7 @@
 
 `tcpdump net {{192.168.1.0/24}}`
 
-- capture all traffic except traffic over port 22 and save to a dump file with today's date
+- capture all traffic except traffic over port 22 and save to a dump file
 
-`tcpdump -w dumpfile.`date +%Y.%m.%d-%H.%M`.pcap not port 22`
+`tcpdump -w dumpfile.pcap not port 22`