libcurl: move site to https

Saves a redirect.

Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/libcurl/libcurl.mk

@@ -6,7 +6,7 @@
 
 LIBCURL_VERSION = 7.51.0
 LIBCURL_SOURCE = curl-$(LIBCURL_VERSION).tar.bz2
-LIBCURL_SITE = http://curl.haxx.se/download
+LIBCURL_SITE = https://curl.haxx.se/download
 LIBCURL_DEPENDENCIES = host-pkgconf \
 	$(if $(BR2_PACKAGE_ZLIB),zlib) \
 	$(if $(BR2_PACKAGE_LIBIDN),libidn) \