改进Connection类connect方法的异常处理 改进Query类一处可能的问题

library/think/db/Connection.php

@@ -286,7 +286,7 @@ abstract class Connection
                     Log::record($e->getMessage(), 'error');
                     return $this->connect($autoConnection, $linkNum);
                 } else {
-                    throw new Exception($e->getMessage());
+                    throw $e;
                 }
             }
         }