fix for "[#11004] Adding ram sound and alt-U causes ram to look like HD sound and can lead to crash"

Missing call sound_initialize_sounds, cant be added BKE_reset_undo since its in blenderkernel.

source/blender/blenkernel/intern/blender.c

@@ -621,7 +621,8 @@ void BKE_write_undo(char *name)
 	}
 }
 
-/* 1= an undo, -1 is a redo. we have to make sure 'curundo' remains at current situation */
+/* 1= an undo, -1 is a redo. we have to make sure 'curundo' remains at current situation
+ * Note, ALWAYS call sound_initialize_sounds after BKE_undo_step() */
 void BKE_undo_step(int step)
 {
 	

source/blender/src/space.c

@@ -1080,7 +1080,10 @@ void BIF_undo_menu(void)
 			if(menu) {
 				short event= pupmenu_col(menu, 20);
 				MEM_freeN(menu);
-				if(event>0) BKE_undo_number(event);
+				if(event>0) {
+					BKE_undo_number(event);
+					sound_initialize_sounds();
+				}
 			}
 		}
 	}