patch 8.0.1200: tests switch the bell off twice

Problem:    Tests switch the bell off twice.
Solution:   Don't set 'belloff' in individual tests. (Christian Brabandt)
diff --git a/src/testdir/test_recover.vim b/src/testdir/test_recover.vim
index 6f7ff2b..a9934a1 100644
--- a/src/testdir/test_recover.vim
+++ b/src/testdir/test_recover.vim
@@ -21,7 +21,7 @@
 " We need about 10000 lines of 100 characters to get two levels of pointer
 " blocks.
 func Test_swap_file()
-  set fileformat=unix undolevels=-1 belloff=all
+  set fileformat=unix undolevels=-1
   edit! Xtest
   let text = "\tabcdefghijklmnoparstuvwxyz0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789abcdefghijklmnoparstuvwxyz0123456789"
   let i = 1