package/libcurl: fix libgsasl support

Contrary to the helptext
https://github.com/curl/curl/blob/master/configure.ac#L152

the configure option is called --with-libgsasl:
https://github.com/curl/curl/blob/master/configure.ac#L1989

Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
Acked-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>

package/libcurl/libcurl.mk

@@ -128,9 +128,9 @@ endif
 
 ifeq ($(BR2_PACKAGE_LIBGSASL),y)
 LIBCURL_DEPENDENCIES += libgsasl
-LIBCURL_CONF_OPTS += --with-gsasl
+LIBCURL_CONF_OPTS += --with-libgsasl
 else
-LIBCURL_CONF_OPTS += --without-gsasl
+LIBCURL_CONF_OPTS += --without-libgsasl
 endif
 
 ifeq ($(BR2_PACKAGE_LIBCURL_COOKIES_SUPPORT),y)