patch 8.1.0334: 'autowrite' takes effect when buffer is not to be written

Problem:    'autowrite' takes effect when buffer is not to be written.
Solution:   Don't write buffers that are not supposed to be written. (Even Q
            Jones, closes #3391)  Add tests for 'autowrite'.
diff --git a/src/version.c b/src/version.c
index c2f64d3..db1f8e2 100644
--- a/src/version.c
+++ b/src/version.c
@@ -795,6 +795,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    334,
+/**/
     333,
 /**/
     332,