tcpdump: print-snmp.c document some ancient history

[Martijn van Duren]

Thanks to benno who found the original reference to this value.
Help out some poor soul who might wander in here in the future.

OK?

martijn@

Index: print-snmp.c
===================================================================
RCS file: /cvs/src/usr.sbin/tcpdump/print-snmp.c,v
retrieving revision 1.25
diff -u -p -r1.25 print-snmp.c
--- print-snmp.c        24 Jan 2020 22:46:37 -0000      1.25
+++ print-snmp.c        23 Oct 2021 09:26:44 -0000
@@ -106,6 +106,7 @@ char *Application[] = {
 #define NSAPADDR 5
        "Counter64",
 #define COUNTER64 6
+/* Defined in RFC1442, removed since RFC1902 */
        "UInteger32"
 #define UINTEGER32 7
 };