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).
Well, it's not that straightforward since for both toaddr and bccaddr we might have either a string or an array of strings but I agree that we need to fix line 255, not the 224.
I will submit a better pull request.