Update facetrack-d to 0.7.6

Author: LunaTheFoxgirl

dub.sdl

@@ -4,7 +4,7 @@ authors "Inochi2D Project"
 copyright "Copyright © 2021, Inochi2D Project"
 license "BSD 2-clause"
 dependency "tinyfiledialogs" version="~>0.10.1"
-dependency "facetrack-d" version="~>0.7.5"
+dependency "facetrack-d" version="~>0.7.6"
 dependency "bindbc-imgui" version="~>0.7.0"
 dependency "inui" version="~>1.0.0"
 dependency "lumars" version="~>1.6.1"