File add_missing_iostream_include.patch of Package octave-forge-optim

--- a/optim-1.5.3/src/error-helpers.h	2019-03-05 14:28:24.967487038 +0100
+++ b/optim-1.5.3/src/error-helpers.h	2019-03-05 14:40:09.977597631 +0100
@@ -18,6 +18,8 @@
 */
 
 #include "config.h"
+
+#include <iostream>
 
 // Octaves non-static verror functions: The elder all set error_state,
 // the newer, present from the time on at which error started to throw