The ornamental design for a fasciagun, as shown and described.
FIG. 1 is a perspective view of a fascia gun showing our new design;
FIG. 2 is a front view thereof;
FIG. 3 is a rear view thereof;
FIG. 4 is a left view thereof;
FIG. 5 is a right view thereof;
FIG. 6 is a top view thereof; and,
FIG. 7 is a bottom view thereof.
The broken line shown in FIG. 7 represent the bound of the design. The broken line and the lighter gray shaded area of the fascia gun encircle by the broken line in FIG. 7 form no part of the claimed design.