patch 8.2.2564: focus events end Insert mode if 'esckeys' is not set

Problem:    Focus events end Insert mode if 'esckeys' is not set.
Solution:   Do not enable focus events when 'esckeys' is off. (closes #7926)
diff --git a/src/version.c b/src/version.c
index 83854d1..f324143 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2564,
+/**/
     2563,
 /**/
     2562,