patch 8.0.0166: JSON with a duplicate key gives an internal error

Problem:    JSON with a duplicate key gives an internal error. (Lcd)
Solution:   Give a normal error.  Avoid an error when parsing JSON from a
            remote client fails.
diff --git a/src/version.c b/src/version.c
index b5039a0..f5327cc 100644
--- a/src/version.c
+++ b/src/version.c
@@ -765,6 +765,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    166,
+/**/
     165,
 /**/
     164,