patch 8.2.2031: some tests fail when run under valgrind

Problem:    Some tests fail when run under valgrind.
Solution:   Avoid timing problems.
diff --git a/src/testdir/test_clientserver.vim b/src/testdir/test_clientserver.vim
index 7a75055..6043184 100644
--- a/src/testdir/test_clientserver.vim
+++ b/src/testdir/test_clientserver.vim
@@ -63,8 +63,9 @@
       call remote_send(name, ":gui -f\<CR>")
     endif
     " Wait for the server to be up and answering requests.
-    sleep 100m
-    call WaitForAssert({-> assert_true(name->remote_expr("v:version", "", 1) != "")})
+    " When using valgrind this can be very, very slow.
+    sleep 1
+    call WaitForAssert({-> assert_match('\d', name->remote_expr("v:version", "", 1))}, 10000)
 
     call remote_send(name, ":let testvar = 'maybe'\<CR>")
     call WaitForAssert({-> assert_equal('maybe', remote_expr(name, "testvar", "", 2))})