I claim the ornamental design for a holder for beverage container, as shown and described.
FIG. 1 is a right side elevation view of a holder for beverage container showing my new design;
FIG. 2 is a left side elevation view thereof;
FIG. 3 is a top plan view thereof;
FIG. 4 is a bottom plan view thereof;
FIG. 5 is a front elevation view thereof; and,
FIG. 6 is a rear elevation view thereof.
The broken lines in FIGS. 1-6 of the holder for beverage container are for the purpose of illustrating environment, and form no part of the claimed design.