Work around http-fetch built with cURL 7.16.0

It appears that curl_easy_duphandle() from libcurl 7.16.0
returns a curl session handle which fails GOOD_MULTI_HANDLE()
check in curl_multi_add_handle().  This causes fetch_ref() to
fail because start_active_slot() cannot start the request.

For now, check for 7.16.0 to work this issue around.

Signed-off-by: Junio C Hamano <junkio@cox.net>

http.h

@@ -18,7 +18,7 @@
 #define curl_global_init(a) do { /* nothing */ } while(0)
 #endif
 
-#if LIBCURL_VERSION_NUM < 0x070c04
+#if (LIBCURL_VERSION_NUM < 0x070c04) || (LIBCURL_VERSION_NUM == 0x071000)
 #define NO_CURL_EASY_DUPHANDLE
 #endif