test: declare that test case use v0.10 explicitly

Without this fix, log rotate configuration in <system> support raises
the following exception:

  Failure: test_inline(ConfigTest):
    Exception raised:
    Fluent::ConfigParseError(<expected end tag '</include>' but got end of file at config_test_1.conf line 11,10
     10:   port 2222
     11:  </source>
         ----------^
    >)

Signed-off-by: Kentaro Hayashi <hayashi@clear-code.com>

test/test_config.rb

@@ -160,7 +160,8 @@ def test_inline
     prepare_config
     opts = {
       :config_path => "#{TMP_DIR}/config_test_1.conf",
-      :inline_config => "<source>\n  type http\n  port 2222\n </source>"
+      :inline_config => "<source>\n  type http\n  port 2222\n </source>",
+      :use_v1_config => false
     }
     assert_nothing_raised do
       Fluent::Supervisor.new(opts)