patch 8.2.2190: Vim9: crash when compiled with EXITFREE

Problem:    Vim9: crash when compiled with EXITFREE.
Solution:   Check that df_ufunc is not NULL.
diff --git a/src/version.c b/src/version.c
index 65dfcdf..427c8f8 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2190,
+/**/
     2189,
 /**/
     2188,