patch 9.0.0589: on AmigaOS4 the pid is available but the task address is used

Problem:    On AmigaOS4 the pid is available but the task address is used.
Solution:   Use getpid().  (Ola Söder, closes #11224)
diff --git a/src/version.c b/src/version.c
index b0f53ab..dedb6cc 100644
--- a/src/version.c
+++ b/src/version.c
@@ -700,6 +700,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    589,
+/**/
     588,
 /**/
     587,