UserStatus: clear status message if message is null

[simonspa]

This fixes #23332

[faily-bot]

🤖 beep boop beep 🤖

Here are the logs for the failed build:

Status of 34915: failure

mysql8.0-php7.4

Show full log

There were 2 warnings:

1) Test\Files\ViewTest::testRenameFailDeleteTargetKeepSource
Trying to configure method "writeStream" which cannot be configured because it does not exist, has not been specified, is final, or is static

2) Test\Files\ViewTest::testCopyFailDeleteTargetKeepSource
Trying to configure method "writeStream" which cannot be configured because it does not exist, has not been specified, is final, or is static

--

There was 1 failure:

1) Test\Files\Node\FolderTest::testRecentFolder
Failed asserting that two arrays are equal.
--- Expected
+++ Actual
@@ @@
 Array (
-    0 => 0
+    0 => 1077
     1 => 1078
 )

/drone/src/tests/lib/Files/Node/FolderTest.php:903

[MorrisJobke]

/backport to stable20