The ornamental design for a strawcap, as shown and described.
FIG. 1 i a front elevational view of a straw cap showing my new design;
FIG. 2 is a rear elevational view thereof;
FIG. 3 is a right side elevational view with the left side being a mirror
image thereof; and,
FIG. 4 is a top view thereof.
The broken line showing of the buckle in FIGS. 1,2, 3, and 4 and a portion
of the strap in FIG. 4 is for illustrative purposes only and forms no part
of the claimed design.