Don't duplicate context menu items for active tab
Don't duplicate context menu items for active tab

`tabId` is always a string, so we should use a `tabId` property of a controller instead.

alexesprit/web-scrobbler,fakelbst/Chrome-Last.fm-Scrobbler,inverse/web-scrobbler,fakelbst/Chrome-Last.fm-Scrobbler,david-sabata/web-scrobbler,carpet-berlin/web-scrobbler,carpet-berlin/web-scrobbler,alexesprit/web-scrobbler,galeksandrp/web-scrobbler,galeksandrp/web-scrobbler,inverse/web-scrobbler,david-sabata/web-scrobbler