The ornamental design for a surveillancecamera, as shown and described.
FIG. 1 is a perspective view of a surveillance camera.
FIG. 2 is a front elevation view thereof.
FIG. 3 is a rear elevation view thereof.
FIG. 4 is a right side elevation view thereof, the left side elevation view being a mirror image thereof; and,
FIG. 5 is a bottom plan view thereof.
The broken lines in the drawings depict subject matter of the surveillance camera that forms no part of the claimed design. The top view of the surveillance camera forms no part of the claimed design.