refusals: a big drop waits for a second member only where there is one

Review 2, N8: a node with one neighbour (a swarm of two, a leaf) never
hears a second member name the change: its big drop was held for good,
an error logged at every REFUSALS. It now waits only where it has
another neighbour than the one telling it; with one, one word is all
there is.

access.md also says what the wait is: it guards against one peer, not
two members saying the same (any node with the swarm key registers),
and never makes a node drop what its own rules take.

1 files changed, 6 insertions, 4 deletions

diff --git a/docs/access.md b/docs/access.md
index 4400b91..03b70b8 100644
--- a/docs/access.md
+++ b/docs/access.md
@@ -302,10 +302,12 @@ everything built on it, its document becoming what it would be without them, and
 its own writes among them in the quarantine (`GET /admin/quarantine`), to be replayed
 or discarded, and the others' among the refused (`GET /admin/refused`, "taken
 unjudged, dropped"); what it writes from then on goes everywhere. A drop taking more
-than 100 changes, or more than ten and a tenth of the document, waits until a second member says so too:
-its own rules and one peer's word could both be off (logged as an error, counted in
-`/admin/stats` as `sync.dropsHeld`). If its rules take the
-change, the two policies disagree, which it logs. A change whose
+than 100 changes, or more than ten and a tenth of the document, waits until a second
+member says so too, where the node has another neighbour to hear it from: its own
+rules and one peer's word could both be off (logged as an error, counted in
+`/admin/stats` as `sync.dropsHeld`). It guards against one peer, not two members
+saying the same; and never makes a node drop what its own rules take. If its rules
+take the change, the two policies disagree, which it logs. A change whose
 dependencies haven't come yet waits for them.
 
 What it doesn't do yet: