chat: fix "open location" feature on windows

+ 3 or 1 slashs in file scheme (rfc1738 3.10)

Change-Id: I77c9be41a5f4b7ca99929d53efbf1883ed127d52

src/messagesadapter.cpp

@@ -204,8 +204,8 @@ MessagesAdapter::openDirectory(const QString& path)
         if (!f.isDir())
             p = f.dir().absolutePath();
         QString url;
-        if (!p.startsWith("file://"))
-            url = "file://" + p;
+        if (!p.startsWith("file:/"))
+            url = "file:///" + p;
         else
             url = p;
         openUrl(url);