Fix warning about missing content type.

test/webrick/test_httpserver.rb

@@ -541,21 +541,25 @@ def test_big_chunks
   end
 
   def test_accept_put_requests
-    TestWEBrick.start_httpserver {|server, addr, port, log|
+    TestWEBrick.start_httpserver do |server, addr, port, log|
       server.mount_proc("/", lambda {|req, res|
         res.status = 200
         assert_equal("abcde", req.body)
       })
+
       Thread.pass while server.status != :Running
 
       Net::HTTP.start(addr, port) do |http|
         req = Net::HTTP::Put.new("/")
         req.body = "abcde"
-        http.request(req){|res|
+        req['content-type'] = "text/plain"
+
+        http.request(req) do |res|
           assert_equal("200", res.code)
-        }
+        end
+
         server.shutdown
       end
-    }
+    end
   end
 end