Fix typo

app/controllers/assignments_controller.rb

@@ -86,7 +86,7 @@ class AssignmentsController < ApplicationController
         @user.assignments.each do |assignment|
           session = assignment.session
           assignees = session.assignments.map { |a| a.user.name }
-          desc [
+          desc = [
             "Assignees: #{assignees.join(', ')}",
             "Speakers: #{session.speakers.map(&:name).join(', ')}",
             session.description