The ornamental design for a flat hiproofbracket, as shown and described.
FIG. 1 is a perspective view from the front of a flat hip roof bracket showing my new design;
FIG. 2 is an elevational view thereof from the front, the elevational view from the rear being identical;
FIG. 3 is a side elevational view thereof from the right, the side elevational view from the left being identical; and,
FIG. 4 is a top plan view thereof, the bottom plan view being identical.
The broken lines in FIGS. 1-2 show portions of the flat hip roof bracket that form no part of the design.
The flat hip roof bracket is shown with a symbolic break in its length. The appearance of any portion of the article between the break lines forms no part of the claimed design.