解决sharedapplication is unavailab

使用网易云信共享屏幕时，pod后IQKeyboardManager提示 sharedapplication is unavailable not available on ios app extension，所以顺便记录下解决方法。

Podfile中增加下面的代码即可解决问题：

post_install do |installer_representation|
installer_representation.pods_project.targets.each do |target|
target.build_configurations.each do |config|
config.build_settings['APPLICATION_EXTENSION_API_ONLY'] = 'NO'
end
end
end