Fixed a few warning messages I ran into today when SMTP had died. We already output...

Fixed a few warning messages I ran into today when SMTP had died.  We already output nice SMTP error messages, so no need to have the PHP code display its own errors.
Also, the property dlv_server_msg was only being set in the errorCheck function, which was never ran if the socket connection failed, so we would get an undefined error.

git-svn-id: https://svn.code.sf.net/p/squirrelmail/code/trunk/squirrelmail@9122 7612ce4b-ef26-0410-bec9-ea0150e637f0