Do not escape slashes for logged exceptions

Signed-off-by: Julius Härtl <jus@bitgrid.net>

lib/private/Log.php

@@ -324,7 +324,7 @@ class Log implements ILogger {
 		try {
 			if ($level >= $minLevel) {
 				if (!$this->logger instanceof IFileBased) {
-					$data = json_encode($data, JSON_PARTIAL_OUTPUT_ON_ERROR);
+					$data = json_encode($data, JSON_PARTIAL_OUTPUT_ON_ERROR | JSON_UNESCAPED_SLASHES);
 				}
 				$this->writeLog($app, $data, $level);
 			}