Fix symlink-directory conflict on upgrade
    
    Due to a years-old stupid limitation of rpm [1], it is not possible to
    upgrade between directory and symlink without ugly hacks, so instead of
    symlinking the include directory, only symlink the individual include
    files inside it.
    
    Without this fix, upgrading quazip-devel or quazip-qt5-devel will fail.
    
    [1] https://bugzilla.redhat.com/show_bug.cgi?id=447156
    
    Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>