debug/gdb: disable nls when CT_TOOLCHAIN_ENABLE_NLS is not selected

Signed-off-by: Zhenqiang Chen <zhenqiang.chen@linaro.org>
Message-Id: <CACgzC7Bn+WpbgDruNeZ4s1z0x1deF6n4YyS22Dy7p_d1fFDVCA@mail.gmail.com>
PatchWork-Id: 191042

 #!/bin/sh

 set -e

 printf "Running autoconf...\n"

 autoconf -Wall --force

 printf "Done. You may now run:\n    ./configure\n"