The ornamental design for an adjustable poppingcork, as shown and described.
FIG. 1 is a top, side perspective view of an adjustable popping cork, showing my new design, shown in a position of use with exemplary environmental subject matter;
FIG. 2 is a side view of the adjustable popping cork, shown with the environmental subject matter removed;
FIG. 3 is a bottom view of the adjustable popping cork; and,
FIG. 4 is a top view of the adjustable popping cork.
The evenly broken lines are shown for the purpose of illustrating both parts of the article as well as environmental subject matter. The dot-dash lines represent the boundaries of the claim. None of the broken lines form part of the claimed design.