vim-patch:8.0.0433: beeps when running tests

Problem:    Quite a few beeps when running tests.
Solution:   Set 'belloff' for these tests. (Christian Brabandt)

c3c766ea8c

src/nvim/testdir/test_visual.vim

@@ -3,6 +3,8 @@ if !has('visual')
   finish
 endif
 
+set belloff=all
+
 func Test_block_shift_multibyte()
   " Uses double-wide character.
   if !has('multi_byte')