Fix current time and duration selectors (#1881)
Fix current time and duration selectors (#1881)

Related to the previous change made for isPlaying ( #1875 ) Only just noticed that duration also broke before that fix. This fixes #1880
carpet-berlin/web-scrobbler,fakelbst/Chrome-Last.fm-Scrobbler,alexesprit/web-scrobbler,fakelbst/Chrome-Last.fm-Scrobbler,carpet-berlin/web-scrobbler,galeksandrp/web-scrobbler,inverse/web-scrobbler,inverse/web-scrobbler,david-sabata/web-scrobbler,galeksandrp/web-scrobbler,david-sabata/web-scrobbler,alexesprit/web-scrobbler