Handle GibbonError when Mailchimp api key was not set (#14695)

* When an api key was not set - handle gibbon error as mailchimp error

see https://app.honeybadger.io/projects/72638/faults/73753178

It's possible the right answer is instead to either (1) not make the
call at all (2) not log as a mailchimp error but treat distinctly

* Only report error if GibbonError, don't attempt to resubscribe

Separate the rescue blocks since resubscribing doesn't make sense if
we're handling a gibbon error rather than a mailchimp error

* Add test for gibbon error being raised (and rescued)

Copied the existing test specifying that resubscribe is attempted on a
raised mailchimp error.

* Remove irrelevant resubscribe check - assert error is handled only

app/services/mailchimp/bot.rb

@@ -41,6 +41,8 @@ module Mailchimp
         )
 
         success = true
+      rescue Gibbon::GibbonError => e
+        report_error(e)
       rescue Gibbon::MailChimpError => e
         # If user was previously subscribed, set their status to "pending"
         return resubscribe_to_newsletter if previously_subcribed?(e)

spec/services/mailchimp/bot_spec.rb

@@ -90,6 +90,15 @@ RSpec.describe Mailchimp::Bot, type: :service do
 
       expect(mailchimp_bot).to have_received(:resubscribe_to_newsletter)
     end
+
+    it "handles GibbonError" do
+      mailchimp_bot = described_class.new(user)
+      gibbon_error =
+        Gibbon::GibbonError.new("You must set an api_key prior to making a call")
+      allow(mailchimp_bot.gibbon).to receive(:upsert).and_raise(gibbon_error)
+
+      expect { mailchimp_bot.upsert_to_newsletter }.not_to raise_error
+    end
   end
 
   describe "manage community moderator list" do