patch 9.0.0361: removing a listener may result in a memory leak

Problem:    Removing a listener may result in a memory leak and remove
            subsequent listerns.
Solution:   Init the "prev" pointer only once. (Yegappan Lakshmanan,
            closes #11039)
diff --git a/src/version.c b/src/version.c
index 4f2b3dc..c6d3869 100644
--- a/src/version.c
+++ b/src/version.c
@@ -708,6 +708,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    361,
+/**/
     360,
 /**/
     359,