patch 8.2.0331: internal error when using test_void() and test_unknown()

Problem:    Internal error when using test_void() and test_unknown().
            (Dominique Pelle)
Solution:   Give a normal error.
diff --git a/src/version.c b/src/version.c
index b883605..c553f20 100644
--- a/src/version.c
+++ b/src/version.c
@@ -739,6 +739,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    331,
+/**/
     330,
 /**/
     329,