patch 8.2.1188: memory leak with invalid json input

Problem:    Memory leak with invalid json input.
Solution:   Free all keys at the end. (Dominique Pellé, closes #6443,
            closes #6442)
diff --git a/src/version.c b/src/version.c
index d0067bf..eaca91f 100644
--- a/src/version.c
+++ b/src/version.c
@@ -755,6 +755,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1188,
+/**/
     1187,
 /**/
     1186,