Ensure that no extra bits can leak into QUrl::toEncoded.

Technically, this function should take QUrl::UrlFormattingOptions, but
that doesn't exist. So we just mask out the high bits that determine
the encoding options. toEncoded only supports one encoding way: fully
encoded.

Change-Id: I1445ad7c292500921ec2672be4524d7d76a39f98
Reviewed-by: David Faure <faure@kde.org>

src/corelib/io/qurl.cpp

@@ -2486,7 +2486,7 @@ QString QUrl::toDisplayString(FormattingOptions options) const
 */
 QByteArray QUrl::toEncoded(FormattingOptions options) const
 {
-    options &= ~DecodeReserved;
+    options &= ~(FullyDecoded | FullyEncoded);
     QString stringForm = toString(options | FullyEncoded);
     return stringForm.toLatin1();
 }