chore: sort stdlib whitelist (#1387)

Fix the order of "encoding/json" as it was out of place.

I stumbled over this yesterday. Nothing about this PR is urgent :)

gnovm/pkg/gnolang/precompile.go

@@ -37,10 +37,10 @@ var stdlibWhitelist = []string{
 	"crypto/md5",
 	"crypto/sha1",
 	"crypto/sha256",
-	"encoding/json",
 	"encoding/base64",
 	"encoding/binary",
 	"encoding/hex",
+	"encoding/json",
 	"encoding/xml",
 	"errors",
 	"flag",