The ornamental design for a windscreenwiperblade, as shown and described.
1. Windscreen wiper blade
1.1 : Perspective
1.2 : Front
1.3 : Back
1.4 : Left
1.5 : Right
1.6 : Top
1.7 : Bottom
The broken lines form no part of the claimed design; the one-dot dash lines represent unclaimed boundary lines and form no part of claimed design; the parallel two-dot dash lines are separation lines, showing that any portion of the article beyond what is shown forms no part of the claimed design.