patch 8.2.3571: some unicode control characters are considered printable

Problem:    Some unicode control characters are considered printable.
Solution:   Make 0x2060 - 0x2069 not printable.
diff --git a/src/version.c b/src/version.c
index 2f19980..43e8615 100644
--- a/src/version.c
+++ b/src/version.c
@@ -758,6 +758,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    3571,
+/**/
     3570,
 /**/
     3569,