patch 8.2.4253: using freed memory when substitute with function call

Problem:    Using freed memory when substitute uses a recursive function call.
Solution:   Make a copy of the substitute text.
diff --git a/src/version.c b/src/version.c
index e5499ad..25dcfe3 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    4253,
+/**/
     4252,
 /**/
     4251,