Fix tests that only worked if object 400 didn't exist

test/controllers/node_controller_test.rb

@@ -455,7 +455,7 @@ class NodeControllerTest < ActionController::TestCase
     end
 
     # check error when a non-existent node is included
-    get :nodes, :params => { :nodes => "#{node1.id},#{node2.id},#{node3.id},#{node4.id},#{node5.id},400" }
+    get :nodes, :params => { :nodes => "#{node1.id},#{node2.id},#{node3.id},#{node4.id},#{node5.id},0" }
     assert_response :not_found
   end
 

test/controllers/relation_controller_test.rb

@@ -188,7 +188,7 @@ class RelationControllerTest < ActionController::TestCase
     end
 
     # check error when a non-existent relation is included
-    get :relations, :params => { :relations => "#{relation1.id},#{relation2.id},#{relation3.id},#{relation4.id},400" }
+    get :relations, :params => { :relations => "#{relation1.id},#{relation2.id},#{relation3.id},#{relation4.id},0" }
     assert_response :not_found
   end
 

test/controllers/way_controller_test.rb

@@ -105,7 +105,7 @@ class WayControllerTest < ActionController::TestCase
     end
 
     # check error when a non-existent way is included
-    get :ways, :params => { :ways => "#{way1.id},#{way2.id},#{way3.id},#{way4.id},400" }
+    get :ways, :params => { :ways => "#{way1.id},#{way2.id},#{way3.id},#{way4.id},0" }
     assert_response :not_found
   end