The ornamental design for a watchcase, as shown and described.
1. Watchcase
1.1 : Perspective
1.2 : Perspective
1.3 : Front
1.4 : Back
1.5 : Top
1.6 : Bottom
1.7 : Right
1.8 : Left
The ornamental design for a watchcase as shown and described; the dotted lines depict portions of the watchcase that form no part of the claimed design.