el/dot-emacs.el (mdw-fontify-rust): Fix integer literal syntax.

[profile] / mdw.conf

### System-specific differences for various dotfiles.

email = mdw@distorted.org.uk
mailbox = ~/Mailbox
rootly = sudo
http-proxy = www-cache.distorted.org.uk:3128
nntp-server = news.distorted.org.uk
cvs-root = metalzone.distorted.org.uk:/home/cvs/cvs
svn-root = svn+ssh://metalzone.distorted.org.uk/home/cvs/svn
cltl-url = https://www.distorted.org.uk/doc/cltl/
hyperspec-url = https://www.distorted.org.uk/doc/hyperspec/
console-ctype = en_GB.UTF-8
x-ctype = en_GB.UTF-8
releasekey = E359CA55
upload-target = ftp.distorted.org.uk:~ftp/pub/mdw/
dput-target = distorted
sbuild-server = universe.distorted.org.uk