patch 8.1.2206: no test for fixed issue #3893

Problem:    No test for fixed issue #3893.
Solution:   Add a test. (Christian Brabandt, #3893)
diff --git a/src/version.c b/src/version.c
index 057ab74..e6a66be 100644
--- a/src/version.c
+++ b/src/version.c
@@ -742,6 +742,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2206,
+/**/
     2205,
 /**/
     2204,