turn off orc program free

stops a crash, makes a memleak

see https://bugzilla.gnome.org/show_bug.cgi?id=731227

libvips/iofuncs/vector.c

@@ -122,7 +122,9 @@ vips_vector_free( VipsVector *vector )
 	printf( "orc_program_free( %s );\n", vector->unique_name ); 
 	printf( "%s = NULL;\n", vector->unique_name ); 
 #endif /*DEBUG_TRACE*/
+	/*
 	VIPS_FREEF( orc_program_free, vector->program );
+	 */
 #endif /*HAVE_ORC*/
 	VIPS_FREE( vector->unique_name );
 	VIPS_FREE( vector );