Stop file ext detection at query param boundaries
Stop file ext detection at query param boundaries

This commit improves Homebrew’s extension detector in `cask/lib/hbc/download_strategy.rb` a bit
so that it won’t cross individual URL query param boundaries any
longer:

```
def ext
  Pathname.new(@url).extname[/[^?&]+/]
end
```

mahori/brew,JCount/brew,MikeMcQuaid/brew,claui/brew,maxim-belkin/brew,DomT4/brew,EricFromCanada/brew,hanxue/linuxbrew,Linuxbrew/brew,Homebrew/brew,maxim-belkin/brew,JCount/brew,vitorgalvao/brew,Homebrew/brew,EricFromCanada/brew,sjackman/homebrew,sjackman/homebrew,ilovezfs/brew,konqui/brew,mahori/brew,mgrimes/brew,claui/brew,mgrimes/brew,MikeMcQuaid/brew,reitermarkus/brew,DomT4/brew,Linuxbrew/brew,sjackman/homebrew,ilovezfs/brew,claui/brew,sjackman/homebrew,konqui/brew,vitorgalvao/brew,hanxue/linuxbrew,Homebrew/brew,mahori/brew,JCount/brew,vitorgalvao/brew,Linuxbrew/brew,maxim-belkin/brew,reitermarkus/brew,nandub/brew,mahori/brew,EricFromCanada/brew,nandub/brew,konqui/brew,nandub/brew,reitermarkus/brew,ilovezfs/brew,MikeMcQuaid/brew,Linuxbrew/brew,JCount/brew,MikeMcQuaid/brew,mgrimes/brew,konqui/brew,Homebrew/brew,vitorgalvao/brew,EricFromCanada/brew,reitermarkus/brew,hanxue/linuxbrew,DomT4/brew,DomT4/brew,claui/brew,nandub/brew