patch 8.1.1158: json encoded string is sometimes missing the final NUL

Problem:    Json encoded string is sometimes missing the final NUL.
Solution:   Add the NUL.  Also for log messages.
diff --git a/src/version.c b/src/version.c
index 4daa41e..7e5d406 100644
--- a/src/version.c
+++ b/src/version.c
@@ -772,6 +772,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1158,
+/**/
     1157,
 /**/
     1156,