CURA-4017 Fix the case when the infill pattern 'lines' may have the zig_zaggify setting enabled, so it never create add but the connection is skipped, but still need to create lines.
CURA-4017 Fix the case when the infill pattern 'lines' may have the zig_zaggify setting
enabled, so it never create add but the connection is skipped, but still
need to create lines.

ROBO3D/CuraEngine,ROBO3D/CuraEngine,Ultimaker/CuraEngine,ROBO3D/CuraEngine,Ultimaker/CuraEngine