User-triggered compaction of view `default/_design/dev_view4` failed: shutdown, when rebalancing out a server node

1) Swap rebalance one node in and out
2) Trigger compaction for production view

We see the following error on all the nodes in the cluster:-
User-triggered compaction of view `default/_design/dev_view4` failed: shutdown. See logs for detailed reason.

We should probably ignore bucket shutdown error.
Along the same lines as
http://www.couchbase.com/issues/browse/MB-6278

[ns_server:warn,2012-08-21T0:57:56.407,ns_1@10.3.121.16:<0.15895.9>:compaction_daemon:do_chain_compactors:520]Compactor for view `default-s/_design/dev_view1` (pid [

{type,view},
{name, <<"default-s/_design/dev_view1">>},
{important,false},
{fa,
{#Fun<compaction_daemon.21.91655267>,
[<<"default-s">>,
<<"_design/dev_view1">>,
{config,
{30, 18446744073709551616},
{30, 18446744073709551616},
undefined,false,
{daemon_config,30,
131072}},
false,bucket]}}]) terminated unexpectedly (ignoring this): {updater_died,
{updater_error,
shutdown}}


[ns_server:warn,2012-08-21T0:17:30.366,ns_1@10.3.121.16:<0.15369.9>:compaction_daemon:do_chain_compactors:515]Compactor for view `default/_design/dev_view4/main` (pid [{type,view}

,

{important,true}

,

{name, <<"default/_design/dev_view4/main">>}

,
{fa,
{#Fun<compaction_daemon.16.5288869>,
[<<"default">>,
<<"_design/dev_view4">>,
main,
{config,

{30, 18446744073709551616},
{30, 18446744073709551616}

,
undefined,false,
{daemon_config,
30,131072}},
true,

{view, <<"_design/dev_view4">>}

]}}]) terminated unexpectedly: shutdown