fix: Adds condition to handle base and mergee contact being same (#2485)

When an agent updates a contact email in the dashboard and the contact also update his email via the email collect box,
Merge action receives the same base and mergee contacts which could cause data corruption.

spec/actions/contact_merge_action_spec.rb

@@ -19,6 +19,14 @@ describe ::ContactMergeAction do
       expect { mergee_contact.reload }.to raise_error(ActiveRecord::RecordNotFound)
     end
 
+    context 'when base contact and merge contact are same' do
+      it 'does not delete contact' do
+        mergee_contact = base_contact
+        contact_merge
+        expect { mergee_contact.reload }.not_to raise_error(ActiveRecord::RecordNotFound)
+      end
+    end
+
     context 'when mergee contact has conversations' do
       it 'moves the conversations to base contact' do
         contact_merge