The ornamental design for a telescopicladder, as shown and described.
FIG. 1 is a front view of a telescopic ladder showing my new design;
FIG. 2 is a rear view thereof;
FIG. 3 is a top perspective view thereof;
FIG. 4 is a bottom perspective view thereof; and,
FIG. 5 is an enlarged view of the indicated portion in FIG. 4.
The dashed broken lines illustrate portions of the telescopic ladder and form no part of the claimed design. The dot-dash broken lines define the bounds of the claimed design and form no part thereof.