Update Autotools Mythbuster link to avoid multiple redirects.

Update Autotools Mythbuster link to avoid multiple redirects.

While I'm hoping to maintain the chain of redirects for the foreseeable
future, it makes sense to point at the final URL now that Autotools
Mythuster has had its domain for a long while.

Change-Id: I6d912e3be0f81b25bec14746ebfee58f29f144b6
Signed-off-by: Diego Elio Pettenò <flameeyes@flameeyes.com>
Reviewed-on: http://openocd.zylin.com/5709
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>
Tested-by: jenkins
Reviewed-by: Tarek BOCHKATI <tarek.bouchkati@gmail.com>
Reviewed-by: Andreas Fritiofson <andreas.fritiofson@gmail.com>