Reword joke password reset email message

Summary: Closes T15840

Test Plan: Send an I forgot my password email with serious business mode off and see the updated email

Reviewers: O1 Blessed Committers, valerio.bozzolan, aklapper

Reviewed By: O1 Blessed Committers, valerio.bozzolan, aklapper

Subscribers: sirocyl, aklapper, speck, tobiaswiese, valerio.bozzolan, Matthew, Cigaryno

Maniphest Tasks: T15840

Differential Revision: https://we.phorge.it/D25671