gnulib: strtoul is considered obsolete and now useless

* bootstrap.conf: here.

bootstrap.conf

@@ -33,7 +33,7 @@ gnulib_modules='
   quote quotearg
   readme-release
   realloc-posix
-  spawn-pipe stdbool stpcpy strdup-posix strerror strtoul strverscmp
+  spawn-pipe stdbool stpcpy strdup-posix strerror strverscmp
   unistd unistd-safer unlink unlocked-io
   update-copyright unsetenv verify
   warnings

lib/.gitignore

@@ -211,8 +211,6 @@
 /stripslash.c
 /strndup.c
 /strnlen.c
-/strtol.c
-/strtoul.c
 /strverscmp.c
 /sys
 /sys_ioctl.h

m4/.gitignore

@@ -144,8 +144,6 @@
 /string_h.m4
 /strndup.m4
 /strnlen.m4
-/strtol.m4
-/strtoul.m4
 /strverscmp.m4
 /sys_ioctl_h.m4
 /sys_socket_h.m4