Fix const warnings in stoken code with NLS disabled
Fix const warnings in stoken code with NLS disabled

The gettext() function will return a non-const 'char *' pointer, and we
should have a cast in the dummy version of the _() macro to do the same.
Otherwise, we get:

../auth.c: In function 'prepare_stoken':
../auth.c:907:15: warning: assignment discards 'const' qualifier from pointer target type [enabled by default]
../auth.c:915:14: warning: assignment discards 'const' qualifier from pointer target type [enabled by default]
../auth.c:922:14: warning: assignment discards 'const' qualifier from pointer target type [enabled by default]
../auth.c:929:14: warning: assignment discards 'const' qualifier from pointer target type [enabled by default]

Based on a patch from Kevin Cernekee.

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

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