[committed] Reset texture id after deleting it

Texture id is not valid after deleting it from gfx card.

So it should be set to 0



Index: src/com/jme/util/TextureManager.java
===================================================================
--- src/com/jme/util/TextureManager.java   (revision 4382)
+++ src/com/jme/util/TextureManager.java   (working copy)
@@ -858,6 +858,7 @@
         TextureState ts = (TextureState)Renderer.defaultStateList[RenderState.StateType.Texture.ordinal()];
         try {
             ts.deleteTextureId(tex.getTextureId());
+            tex.setTextureId(0);
         } catch (Exception e) {
         } // ignore.
     }