Fixed rake task description (#2248)

The department affiliations rake task has the wrong description, this
fixes it.

Author: kelynch

lib/tasks/load_departments.rake

@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 namespace :load_affiliations do
-  desc "Load in users from the registration list"
+  desc "Load department affiliations from a file"
   task :from_file, [:department_file] => [:environment] do |_, args|
     Affiliation.load_from_file(args[:department_file])
   end

lib/tasks/load_users.rake

@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 namespace :load_users do
-  desc "Load user from ldap"
+  desc "Load users from LDAP"
   task from_ldap: :environment do
     count_before = User.count
     PrincetonUsers.create_users_from_ldap