Revert "add mix_wall revert infill_overlap"

This reverts commit 04b1c22cc6.

src/libslic3r/PrintConfig.hpp

@@ -133,15 +133,13 @@ enum DraftShield {
 enum class LabelObjectsStyle {
     Disabled, Octoprint, Firmware
 };
-//w20
 enum class PerimeterGeneratorType
 {
     // Classic perimeter generator using Clipper offsets with constant extrusion width.
     Classic,
     // Perimeter generator with variable extrusion width based on the paper
     // "A framework for adaptive width control of dense contour-parallel toolpaths in fused deposition modeling" ported from Cura.
-    Arachne,
-    Mix_wall
+    Arachne
 };
 //B3
 enum class GCodeThumbnailsFormat { QIDI,PNG, JPG, QOI };