The design consists of the visual features of the GLASSWARE HOLDER, as shown in the drawings, whether those visual features are features of shape, configuration, pattern or ornament, or any combination of these features. The portions in dashed lines do not form part of the design.Fig. 1 is a perspective view of a glassware holder in accordance with the present design, shown with glassware as part of the surrounding environment;Fig. 2 is a perspective view of the design of Fig. 1;Fig. 3 is a side view of the design of Fig. 1;Fig. 4 is an end view of the design of Fig. 1;Fig. 5 is a top view of the design of Fig. 1; andFig. 6 is a bottom view of the design of Fig. 1.