make the description of geoip-client-origins more true to the code

svn:r16579

doc/spec/dir-spec.txt

@@ -625,10 +625,9 @@ $Id$
         Non-bridges SHOULD NOT generate these fields.  Contains a list
         of mappings from two-letter country codes (CC) to the number
         of clients that have connected to that bridge from that
-        country (approximate, and rounded to the nearest multiple of 8
+        country (approximate, and rounded up to the nearest multiple of 8
         in order to hamper traffic analysis).  A country is included
-        only if it has at least 8 addresses, and only if the bridge
+        only if it has at least one address.  The time in
-        has seen at least 16 addresses total.  The time in
         "geoip-start" is the time at which we began collecting geoip
         statistics.