The ornamental design for a spraygun, as shown and described.
1. Spray gun
1.1 : Front
1.2 : Back
1.3 : Top
1.4 : Bottom
1.5 : Left
1.6 : Right
1.7 : Perspective view showing front side
1.8 : Perspective view showing rear side
The alternating long and short broken lines immediately adjacent the shaded areas represent the bounds of the claimed design while all other broken lines are included for the purpose of illustrating portions of the spray gun; the broken lines form no part of the claimed design.