fix: Undefined method `encode' for nil for avatar from url job (#10450)

Invalid urls supplied to the job was causing sentry issues. The issue primarily occurs when the download file.original_filename comes out as empty

fixes: https://github.com/chatwoot/chatwoot/issues/10449

spec/jobs/avatar/avatar_from_url_job_spec.rb

@@ -17,4 +17,20 @@ RSpec.describe Avatar::AvatarFromUrlJob do
     described_class.perform_now(avatarable, avatar_url)
     expect(avatarable.avatar).to be_attached
   end
+
+  # ref: https://github.com/chatwoot/chatwoot/issues/10449
+  it 'will not throw error if the avatar url is not valid and the file does not have a filename' do
+    # Create a temporary file with no filename and content type application/xml
+    temp_file = Tempfile.new(['invalid', '.xml'])
+    temp_file.write('<invalid>content</invalid>')
+    temp_file.rewind
+
+    expect(Down).to receive(:download).with(avatar_url, max_size: 15 * 1024 * 1024)
+                                      .and_return(ActionDispatch::Http::UploadedFile.new(tempfile: temp_file, type: 'application/xml'))
+
+    expect { described_class.perform_now(avatarable, avatar_url) }.not_to raise_error
+
+    temp_file.close
+    temp_file.unlink # deletes the temp file
+  end
 end