Fix Mapster32 bug where pressing "O" on a sprite twice would corrupt your map due to unchecked use of hitscan results.

git-svn-id: https://svn.eduke32.com/eduke32@4901 1a8010ca-5511-0410-912e-c29ae57300e0

polymer/eduke32/build/src/build.c

@@ -2075,6 +2075,9 @@ void DoSpriteOrnament(int32_t i)
             0,
             &hit,CLIPMASK1);
 
+    if (hit.sect == -1)
+        return;
+
     sprite[i].x = hit.pos.x;
     sprite[i].y = hit.pos.y;
     sprite[i].z = hit.pos.z;