Fallback to normal undo when wire-drawing not in progress.

Fixes https://gitlab.com/kicad/code/kicad/-/issues/16216

(cherry picked from commit 035725cd5d)

eeschema/tools/sch_line_wire_bus_tool.cpp

@@ -937,6 +937,11 @@ int SCH_LINE_WIRE_BUS_TOOL::doDrawSegments( const TOOL_EVENT& aTool, int aType,
                         m_view->AddToPreview( wire->Clone() );
                 }
             }
+            else if( evt->IsAction( &ACTIONS::undo ) )
+            {
+                // Dispatch as normal undo event
+                evt->SetPassEvent();
+            }
             else
             {
                 wxBell();