Fix -Wc++11-narrowing error in qtextmarkdownimporter

error: non-constant-expression cannot be narrowed from type
'qt::QFlags::Int' (aka 'int') to 'unsigned int' in initializer list [-Wc++11-narrowing]

Change-Id: Ic634a98d29a108741d41955da1fbf2c986e4a943
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>

src/gui/text/qtextmarkdownimporter.cpp

@@ -117,7 +117,7 @@ void QTextMarkdownImporter::import(QTextDocument *doc, const QString &markdown)
 {
     MD_PARSER callbacks = {
         0, // abi_version
-        m_features,
+        unsigned(m_features),
         &CbEnterBlock,
         &CbLeaveBlock,
         &CbEnterSpan,