Fix call on nil for in-product marketing email

This fixes an issue with the in-product marketing emails, where we
called `.html_safe` on the second body line, which can be `nil`.

It also fixes a deprecation warning for the `inline_image_link` where
`options` was passed as a keyword argument.

app/helpers/in_product_marketing_helper.rb

@@ -343,7 +343,7 @@ module InProductMarketingHelper
     end
   end
 
-  def inline_image_link(folder, image, **options)
+  def inline_image_link(folder, image, options)
     attachments.inline[image] = File.read(Rails.root.join("app/assets/images", folder, image))
     image_tag attachments[image].url, **options
   end

app/views/notify/in_product_marketing_email.html.haml

@@ -177,8 +177,9 @@
                       %td{ style: "padding: 10px 20px 30px 20px; font-family: 'Source Sans Pro', helvetica, arial, sans-serif; color:#000000; font-size: 18px; line-height: 24px;" }
                         %p{ style: "margin: 0 0 20px 0;" }
                           = in_product_marketing_body_line1(@track, @series, format: :html).html_safe
-                        %p{ style: "margin: 0 0 20px 0;" }
-                          = in_product_marketing_body_line2(@track, @series, format: :html).html_safe
+                        - in_product_marketing_body_line2(@track, @series, format: :html)&.tap do |line|
+                          %p{ style: "margin: 0 0 20px 0;" }
+                            = line.html_safe
                     %tr
                       %td{ align: "center", style: "padding: 10px 20px 80px 20px; font-family: 'Source Sans Pro', helvetica, arial, sans-serif;" }
                         .cta_link= cta_link(@track, @series, @group, format: :html)

spec/mailers/emails/in_product_marketing_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+require 'email_spec'
+
+RSpec.describe Emails::InProductMarketing do
+  include EmailSpec::Matchers
+  include InProductMarketingHelper
+
+  let_it_be(:user) { create(:user) }
+  let_it_be(:group) { create(:group) }
+
+  describe '#in_product_marketing_email' do
+    using RSpec::Parameterized::TableSyntax
+
+    where(:track, :series) do
+      :create | 0
+      :create | 1
+      :create | 2
+      :verify | 0
+      :verify | 1
+      :verify | 2
+      :trial  | 0
+      :trial  | 1
+      :trial  | 2
+      :team   | 0
+      :team   | 1
+      :team   | 2
+    end
+
+    with_them do
+      subject { Notify.in_product_marketing_email(user.id, group.id, track, series) }
+
+      it 'has the correct subject and content' do
+        aggregate_failures do
+          is_expected.to have_subject(subject_line(track, series))
+          is_expected.to have_body_text(in_product_marketing_title(track, series))
+          is_expected.to have_body_text(in_product_marketing_subtitle(track, series))
+          is_expected.to have_body_text(in_product_marketing_cta_text(track, series))
+        end
+      end
+    end
+  end
+end