fix: use CoverArtID if available and LastFM image url otherwise

ui/browsing/artistpage.go

@@ -459,10 +459,12 @@ func (a *ArtistPageHeader) Update(artist *mediaprovider.ArtistWithAlbums, im *ba
 	a.favoriteBtn.IsFavorited = artist.Favorite
 	a.favoriteBtn.Refresh()
 	a.artistID = artist.ID
-	a.artistImageID = artist.CoverArtID
 	a.titleDisp.Segments[0].(*widget.TextSegment).Text = artist.Name
 	a.titleDisp.Refresh()
-
+	if artist.CoverArtID == "" {
+		return
+	}
+	a.artistImageID = artist.CoverArtID
 	go func() {
 		if cover, err := im.GetCoverThumbnail(artist.CoverArtID); err == nil {
 			a.artistImage.SetImage(cover, true)
@@ -520,6 +522,11 @@ func (a *ArtistPageHeader) UpdateInfo(info *mediaprovider.ArtistInfo) {
 }
 
 func (a *ArtistPageHeader) showPopUpCover() {
+	if a.artistImageID == "" {
+		if im := a.artistImage.Image(); im != nil {
+			a.artistPage.contr.ShowPopUpImage(im)
+		}
+	} else {
 		if a.fullSizeCoverFetching {
 			return
 		}
@@ -534,6 +541,7 @@ func (a *ArtistPageHeader) showPopUpCover() {
 			a.artistPage.contr.ShowPopUpImage(cover)
 		}
 	}
+}
 
 func (a *ArtistPageHeader) toggleFavorited() {
 	params := mediaprovider.RatingFavoriteParameters{ArtistIDs: []string{a.artistID}}