The ornamental design for a vacuumcleaner, as shown and described.
1. Vacuum cleaner
1.1: Top right front perspective view;
1.2: Front elevational view;
1.3: Rear elevational view;
1.4: Left side elevational view:
1.5: Right side elevational view:
1.6: Top plan view;
1.7: Bottom plan view;
1.8: Top right front perspective view with an unattached unclaimed vacuum cleaner suction nozzle shown in broken lines forming no part of the claim; and
1.9: Top right front perspective view with an attached unclaimed vacuum cleaner suction nozzle shown in broken lines forming no part of the claim.