build: remove automake and autoconf from bootstrap deps

Bootstrap checks these dependencies anyway, and the versions given were
out of sync with the canonical requirements (in configure.ac) and way
out of date.

diff --git a/bootstrap.conf b/bootstrap.conf
line changes: +0/-2
index e2fb8a5..acb948c
--- a/bootstrap.conf
+++ b/bootstrap.conf

@@ -83,8 +83,6 @@ gnulib_tool_option_extras="--makefile-name=gnulib.mk --automake-subdir"
 
 # Build prerequisites
 buildreq="\
-autoconf   2.59
-automake   1.9.6
 git        1.5.5
 tar        -
 "