Miscutils: fix for send_email error on DEV site

* For the DEV site send_email function was failing while trying to
  concatenate list and string (because the CFG_SITE_ADMIN_EMAIL
  was not a list).
Indeed, my bad. [`sendmail`](http://hg.python.org/cpython/file/2.7/Lib/smtplib.py#l726) really expects a list, your solution + a `split`?