curl: Use wolfssl by default

Instead of using mbedtls by default use wolfssl. We now integrate
wolfssl in the default build so use it also as default ssl library for
curl.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>

net/curl/Config.in

@@ -4,7 +4,7 @@ comment "SSL support"
 
 choice
 	prompt "Selected SSL library"
-	default LIBCURL_MBEDTLS
+	default LIBCURL_WOLFSSL
 
 	config LIBCURL_MBEDTLS
 		bool "mbed TLS"