The ornamental design for a shotgunribsight, as shown and described.
FIG. 1 is an isometric view of a shotgun rib sight;
FIG. 2 is a side elevational view thereof;
FIG. 3 is a bottom plan view thereof;
FIG. 4 is a top plan view thereof; and,
FIG. 5 is a segmented isometric view thereof.
Lines shown in FIGS. 1-5 that form shading indicate the character and contour of surfaces and 3-dimensional aspects of the design. The broken line showing in FIGS. 1, 2, 3, and 5 is included for the purpose of illustrating portions of the claimed design that forms no part of the claimed design.