Remove unused variable and add missing define

xs/src/ExPolygon.cpp

@@ -57,7 +57,6 @@ ExPolygon::to_AV() {
     AV* av = newAV();
     av_extend(av, num_holes);  // -1 +1
     
-    SV* sv = newSV(0);
     av_store(av, 0, this->contour.to_SV_ref());
     
     for (unsigned int i = 0; i < num_holes; i++) {

xs/src/MultiPoint.cpp

@@ -38,6 +38,7 @@ MultiPoint::first_point() const
     return new Point(this->points.front());
 }
 
+#ifdef SLIC3RXS
 void
 MultiPoint::from_SV(SV* poly_sv)
 {
@@ -82,5 +83,6 @@ MultiPoint::to_SV_pureperl() const {
     }
     return newRV_noinc((SV*)av);
 }
+#endif
 
 }