set APT::Sources::Use-Deb822 to default false for now

apt-pkg/sourcelist.cc

@@ -297,7 +297,7 @@ bool pkgSourceList::Read(string File)
 /* */
 bool pkgSourceList::ReadAppend(string File)
 {
-   if (_config->FindB("APT::Sources::Use-Deb822", true) == true)
+   if (_config->FindB("APT::Sources::Use-Deb822", false) == true)
    {
       int lines_parsed =ParseFileDeb822(File);
       if (lines_parsed < 0)