Put xml.o before main.o in build.
Put xml.o before main.o in build.

Just observed a strange failure when someone tried to override CFLAGS when
invoking make. It build main.o happily, but then fell over trying to build
xml.o. Then they tried again, overriding OPT_FLAGS instead. But main.o
wasn't rebuilt, and had been built without -DOPENCONNECT_LIBPROXY, hence
had a different 'struct openconnect_info' to the rest of the program, leading
to weird faults.

Ideally we ought to remember the flags used for each build and compare; the
kernel and chromium makefiles have the required magic for that which could
be easily stolen. But for now the easy fix is just to build xml.o first.
That way, if someone overrides CFLAGS they'll get an immediate failure and
no stray objects with wrong struct layout.

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

nmav/openconnect-mine,matlockx/openconnect,cernekee/openconnect,mtmiller/openconnect,mveplus/openconnect-client,don-johnny/openconnect,brandt/openconnect,brandt/openconnect,liiir1985/openconnect,sihde/openconnect,chadcatlett/openconnect,lins05/openconnect,don-johnny/openconnect,mtmiller/openconnect,neshema/openconnect,lins05/openconnect,chadcatlett/openconnect,neshema/openconnect,don-johnny/openconnect,brandt/openconnect,matlockx/openconnect,neshema/openconnect,sihde/openconnect,liiir1985/openconnect,mtmiller/openconnect,mdutton3/OpenConnect,atyndall/openconnect,chadcatlett/openconnect,nmav/openconnect-mine,cernekee/openconnect,don-johnny/openconnect,lins05/openconnect,liiir1985/openconnect,matlockx/openconnect,atyndall/openconnect,sihde/openconnect,matlockx/openconnect,mdutton3/OpenConnect,lins05/openconnect,certik/openconnect,mveplus/openconnect-client,brandt/openconnect,certik/openconnect,mdutton3/OpenConnect,neshema/openconnect,cernekee/openconnect,atyndall/openconnect,nmav/openconnect-mine,chadcatlett/openconnect,mtmiller/openconnect,mveplus/openconnect-client,atyndall/openconnect,nmav/openconnect-mine,mveplus/openconnect-client,liiir1985/openconnect,certik/openconnect,cernekee/openconnect