minor: testing fixes

test/replica_sets/read_preference_test.rb

@@ -108,6 +108,7 @@ class ReadPreferenceTest < Test::Unit::TestCase
       @coll.save({:a => 50}, :safe => {:w => 2, :wtimeout => 10000})
     end
     @rs.restart_killed_nodes
+    sleep(1)
     @coll.save({:a => 50}, :safe => {:w => 2, :wtimeout => 10000})
     assert_equal 4, @coll.find.to_a.length
   end

test/replica_sets/refresh_with_threads_test.rb

@@ -49,6 +49,8 @@ class ReplicaSetRefreshWithThreadsTest < Test::Unit::TestCase
 
     @rs.add_node
     threads.each {|t| t.join }
+
+    sleep(1)
     
     @conn['admin'].command({:ismaster => 1})