patch 9.0.0790: test for dummy buffer does not always produce the E86 error

Problem:    Test for dummy buffer does not always produce the E86 error.
Solution:   Do not check if the error is produced.
diff --git a/src/version.c b/src/version.c
index 05e619f..2186bc8 100644
--- a/src/version.c
+++ b/src/version.c
@@ -696,6 +696,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    790,
+/**/
     789,
 /**/
     788,