The ornamental design for a solar foldingwalllamp, as shown and described.
FIG. 1 is a front perspective view of a solar folding wall lamp showing my new design;
FIG. 2 is a rear perspective view thereof;
FIG. 3 is a front elevational view thereof;
FIG. 4 is a rear elevational view thereof;
FIG. 5 is a left side view thereof;
FIG. 6 is a right side view thereof;
FIG. 7 is a top plan view thereof;
FIG. 8 is a bottom plan view thereof; and,
FIG. 9 is a front perspective view of the solar folding wall lamp in a folded state.
The broken lines in the figures are for the purposes of illustrating portions of the solar folding wall lamp, which form no part of the claimed design.