:DeinUpdate runs "build" everytime (even if nothing changed)

[unclechu]

I have for example LanguageClient-neovim, which have build section:
https://github.com/unclechu/neovimrc/blob/369e1bef97e372074fb13137f7507f138b6ba050/plugins.vim#L42-L45

call dein#add('autozimu/LanguageClient-neovim', {
	\ 'rev': 'next',
	\ 'build': 'bash install.sh',
	\ })

This build script downloads a binary executable which on poor internet connection could take relatively long. But if you call call dein#update() it wont run build command if there's no new commits received for a plugin, and everything is fastly done. I think dein-ui supposed to behave the same way, don't you think?

[wsdjeg]

Ok, I Should add this option, but I need to take a look how dein support this feature.