Change man page section.

--- a/tcpdump.1.in
+++ b/tcpdump.1.in
@@ -20,7 +20,7 @@
 .\" WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
 .\" MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 .\"
-.TH TCPDUMP 1  "21 December 2020"
+.TH TCPDUMP 8  "21 December 2020"
 .SH NAME
 tcpdump \- dump traffic on a network
 .SH SYNOPSIS