Limit the size of the PTH hole walls

Should always be at least 2px thick but no larger than the minimum
thickness of the pad (walls do not extend beyond the pad itself)

pcbnew/pcb_painter.cpp

@@ -1436,6 +1436,13 @@ void PCB_PAINTER::draw( const PAD* aPad, int aLayer )
         m_gal->SetIsStroke( false );
         double widthFactor = ADVANCED_CFG::GetCfg().m_HoleWallPaintingMultiplier;
         double lineWidth = widthFactor * m_holePlatingThickness;
+
+        // Prevent the hole wall from being drawn too thin (at least two pixels)
+        // or too thick (cap at the size of the pad )
+        lineWidth = std::max( lineWidth, 2.0 / m_gal->GetWorldScale() );
+        lineWidth = std::min( lineWidth, aPad->GetSizeX() / 2.0 );
+        lineWidth = std::min( lineWidth, aPad->GetSizeY() / 2.0 );
+
         m_gal->SetFillColor( color );
 
         std::shared_ptr<SHAPE_SEGMENT> slot = aPad->GetEffectiveHoleShape();