Make authentication valgrind-friendly
Make authentication valgrind-friendly

Not strictly needed to free stuff right before we exit, but it makes it
easier to find leaks in the library code.

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

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