Fix another 7.3 test output difference with phpdbg

Author: kabel

tests/Regression/GitHub/2591-separate-function-no-preserve-no-bootstrap-php73.phpt

@@ -28,12 +28,10 @@ Time: %s, Memory: %s
 There were 2 errors:
 
 1) Issue2591_SeparateFunctionNoPreserveTest::testChangedGlobalString
-PHPUnit\Framework\Exception: %sUncaught Error: Class 'PHPUnit\Framework\TestCase' not found in %s/SeparateFunctionNoPreserveTest.php:%d%S
-Stack trace:
+PHPUnit\Framework\Exception: %sUncaught Error%sin %s
 %a
 2) Issue2591_SeparateFunctionNoPreserveTest::testGlobalString
-PHPUnit\Framework\Exception: PHP Fatal error:  Uncaught Error: Class 'PHPUnit\Framework\TestCase' not found in %s:%d
-Stack trace:
+PHPUnit\Framework\Exception: %sUncaught Error%sin %s
 %a
 ERRORS!
 Tests: 2, Assertions: 0, Errors: 2.