patch 8.2.0237: crash when setting 'wincolor' on finished terminal window

Problem:    Crash when setting 'wincolor' on finished terminal window.
            (Bakudankun)
Solution:   Check that the vterm is not NULL. (Yasuhiro Matsumoto, closes
            #5607, closes #5610)
diff --git a/src/version.c b/src/version.c
index 7ca6baa..7c48e0b 100644
--- a/src/version.c
+++ b/src/version.c
@@ -743,6 +743,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    237,
+/**/
     236,
 /**/
     235,