Remove or fix Sendgrid email

[btrd]

From my test it seems the Sendgrind account isn't working anymore, check with other if it indeed the case and if we can remove it.

[adrienpoly]

I seen two locations where emails are used :

• password reset (this is internal only as the only users are the admins)
• an email that was due to be sent after submitting a talk

If the current account is lost maybe the better solution would be to create a new one under the new org and link it