Ensure GithubImport::Client does not crash when the 'verify_ssl' config is not present

Settingslogic allow to access optional settings through the Hash
notation: if the key is not present, it returns nil. In the present case
this will let the Octokit::Client object use whatever default value it
wants for the ssl option.

lib/gitlab/github_import/client.rb

@@ -17,7 +17,7 @@ module Gitlab
             access_token: access_token,
             api_endpoint: github_options[:site],
             connection_options: {
-              ssl: { verify: config.verify_ssl }
+              ssl: { verify: config['verify_ssl'] }
             }
           )
         end

spec/lib/gitlab/github_import/client_spec.rb

@@ -2,7 +2,7 @@ require 'spec_helper'
 
 describe Gitlab::GithubImport::Client, lib: true do
   let(:token) { '123456' }
-  let(:github_provider) { OpenStruct.new(app_id: 'asd123', app_secret: 'asd123', name: 'github', args: { 'client_options' => {} }) }
+  let(:github_provider) { Settingslogic.new('app_id' => 'asd123', 'app_secret' => 'asd123', 'name' => 'github', 'args' => { 'client_options' => {} }) }
 
   subject(:client) { described_class.new(token) }
 
@@ -16,6 +16,9 @@ describe Gitlab::GithubImport::Client, lib: true do
     end
   end
 
+  it 'does not crash (e.g. Settingslogic::MissingSetting) when verify_ssl config is not present' do
+    expect { client.api }.not_to raise_error
+  end
 
   context 'allow SSL verification to be configurable on API' do
     before do