Add newline when writing logs to stdout (#7418)

Add newline on the end of the line when printing to stdout.

program/lib/Roundcube/rcube.php

@@ -1272,7 +1272,7 @@ class rcube
         // write message with file name when configured to log to STDOUT
         if ($log_driver == 'stdout') {
             $stdout = "php://stdout";
-            $line = "$name: $line";
+            $line = "$name: $line\n";
             return file_put_contents($stdout, $line, FILE_APPEND) !== false;
         }