Fix race condition in test 06-main-compaction.t

Ensure that automatic cleanup is disabled before adding
partition for cleanup and verifying the index state was
updated to reflect that state transition.

Change-Id: I1334f4ac0e851fa754ec0d28468ea3134d5150fa
Reviewed-on: http://review.couchbase.org/24012
Tested-by: Filipe David Borba Manana <fdmanana@gmail.com>
Reviewed-by: Volker Mische <volker.mische@gmail.com>
Reviewed-by: Filipe David Borba Manana <fdmanana@gmail.com>

src/couch_set_view/test/06-main-compaction.t

@@ -67,6 +67,8 @@ test() ->
     DiskSizeBefore = main_index_disk_size(),
 
     verify_group_info_before_cleanup_request(),
+    GroupPid = couch_set_view:get_group_pid(test_set_name(), ddoc_id()),
+    ok = gen_server:call(GroupPid, {set_auto_cleanup, false}, infinity),
     ok = couch_set_view:set_partition_states(test_set_name(), ddoc_id(), [], [], lists:seq(8, 63)),
     verify_group_info_after_cleanup_request(),