Keep free_supporting_certs array to remember which to free
Keep free_supporting_certs array to remember which to free

This replaces the 'certs_to_free' variable, which was only capable of
specifying the first N certs.

Signed-off-by: David Woodhouse <b460d66aaf00c296a3db1c1d9eeafc081d5f7d70@intel.com>

don-johnny/openconnect,atyndall/openconnect,brandt/openconnect,don-johnny/openconnect,mveplus/openconnect-client,lins05/openconnect,lins05/openconnect,mtmiller/openconnect,matlockx/openconnect,matlockx/openconnect,neshema/openconnect,brandt/openconnect,cernekee/openconnect,mtmiller/openconnect,nmav/openconnect-mine,mveplus/openconnect-client,mveplus/openconnect-client,liiir1985/openconnect,chadcatlett/openconnect,cernekee/openconnect,atyndall/openconnect,lins05/openconnect,mtmiller/openconnect,lins05/openconnect,chadcatlett/openconnect,mtmiller/openconnect,cernekee/openconnect,nmav/openconnect-mine,nmav/openconnect-mine,don-johnny/openconnect,neshema/openconnect,matlockx/openconnect,neshema/openconnect,cernekee/openconnect,brandt/openconnect,matlockx/openconnect,chadcatlett/openconnect,atyndall/openconnect,brandt/openconnect,neshema/openconnect,chadcatlett/openconnect,liiir1985/openconnect,nmav/openconnect-mine,mveplus/openconnect-client,atyndall/openconnect,don-johnny/openconnect,liiir1985/openconnect,liiir1985/openconnect