Remove a the necessity of a few weak vtables

For background, see QTBUG-45582.

Change-Id: I6c4758ce62149437c26971056b465d5dbd2b13b0
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

src/plugins/vcsbase/vcsbaseclientsettings.cpp

@@ -75,6 +75,8 @@ VcsBaseSettings::VcsBaseSettings()
     timeout.setSuffix(tr("s"));
 }
 
+VcsBaseSettings::~VcsBaseSettings() = default;
+
 FilePaths VcsBaseSettings::searchPathList() const
 {
     return Utils::transform(path.value().split(HostOsInfo::pathListSeparator(), Qt::SkipEmptyParts),