patch 8.2.0689: when using getaddrinfo() the error message is unclear

Problem:    When using getaddrinfo() the error message is unclear.
Solution:   Use gai_strerror() to get the message. (Ozaki Kiichi,
            closes #6034)
diff --git a/src/version.c b/src/version.c
index fcc897a..c083372 100644
--- a/src/version.c
+++ b/src/version.c
@@ -747,6 +747,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    689,
+/**/
     688,
 /**/
     687,