Update ad-hoc patch for obstacles for Flexlib & StdCellLib.

* Bug: In Katana::PowerRailsPlane::Rail::doLayout(), to avaid tracks too
    close to an offgrid obstacle in the preferred routing direction, we
    expand the width/height of the segment by one pitch. BUT it seems to
    still be too close for Flexlib and StdCellLib, so there is an ad-hoc
    patch based on the *name* of the cell library. Update it to take
    "StdCellLib" into account.

katana/src/PowerRails.cpp

@@ -492,6 +492,9 @@ namespace {
           delta = plane->getLayerGauge()->getPitch();
         }
       }
+      if (AllianceFramework::get()->getCellGauge()->getName() == Name("StdCellLib")) {
+        delta = plane->getLayerGauge()->getPitch();
+      }
     }
 
     cdebug_log(159,0) << "  delta:" << DbU::getValueString(delta)