Please update config.guess before the 5.1 branch

[rbrown64@csc.com.au]

The config.guess used by gcc-3.0 and binutils-2.11 renders UnixWare 7.1.0
as `i586-sco-sysv5uw7.1.0' and the one used in the 20010707 gdb snapshot
as `i585-UnixWare7.1.0-sysv5'.
Please update the gdb config.guess to match before the 5.1 branch.

< http://sources.redhat.com/ml/gdb-testresults/2001-07/msg00000.html >