The ornamental design for an electrickettle, as shown and described.
1. Electric kettle
1.1: Front
1.2: Back
1.3: Left
1.4: Right
1.5: Top
1.6 Bottom
1.7 Perspective
1.8 Reference view of state of use
The broken lines in reproduction 1.6 depict portions of the electric kettle that form no part of the claimed design. The broken lines in reproduction 1.8 depict environmental subject matter that forms no part of the claimed design. The oblique lines at the top of the electric kettle depict reflective surfaces.