Remove the obsolete cc option

Remove the obsolete cc option

If sarg is compiled with cc, the old configure script would add the -Aa
option to the CFLAGS but that option produces an error on modern cc. The
error is about a missing argument. I could not find the new syntax nor the
purpose of that option but it was reported that removing the whole
condition was solving the problem.

Bug report here:

http://sourceforge.net/tracker/?func=detail&aid=3467463&group_id=68910&atid=522791