net: lwip: Enable https:// support for wget

With the recent changes of lwip & mbedTLS we can now download from
https:// urls instead of just http://.
Adjust our wget lwip version parsing to support both URLs.
While at it adjust the default TCP window for QEMU since https seems to
require at least 16384

Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Jerome Forissier <jerome.forissier@linaro.org>
diff --git a/net/lwip/Kconfig b/net/lwip/Kconfig
index 8a67de4..a9ae9bf 100644
--- a/net/lwip/Kconfig
+++ b/net/lwip/Kconfig
@@ -37,7 +37,7 @@
 
 config LWIP_TCP_WND
 	int "Value of TCP_WND"
-	default 8000 if ARCH_QEMU
+	default 32768 if ARCH_QEMU
 	default 3000000
 	help
 	  Default value for TCP_WND in the lwIP configuration