Fix synchronization issues of folders with non-ascii chars

The problem was that listContextForUser function was generating an url different that the one returned when the folder is created.

For example for spanish clients "Sync issues" folder is called "Problemas de sincronización" (notice the 'ó'). When that folder was being created the url returned by sogo (and stored in openchangedb) was something like:

    sogo://user1:user1@mail/folderProblemas_SP_de_SP_sincronizaci&APM-n/

Then, in the next connection the listContextsForUser functions returned a different url:

    sogo://user1:user1@mail/folderProblemas_SP_de_SP_sincronizaci_AM_APM-n/