Update RestController.php

I propose this simple change so that in case $row is false, the message 'text_rest_invalid_api_key' has the information in '$this->rest->key' to display it correctly.

Author: alex-monte

src/RestController.php

@@ -867,12 +867,13 @@ protected function _detect_api_key()
 
         // Find the key from server or arguments
         if (($key = isset($this->_args[$api_key_variable]) ? $this->_args[$api_key_variable] : $this->input->server($key_name))) {
+
+            $this->rest->key = $key;
+
             if (!($row = $this->rest->db->where($this->config->item('rest_key_column'), $key)->get($this->config->item('rest_keys_table'))->row())) {
                 return false;
             }
 
-            $this->rest->key = $row->{$this->config->item('rest_key_column')};
-
             isset($row->user_id) && $this->rest->user_id = $row->user_id;
             isset($row->level) && $this->rest->level = $row->level;
             isset($row->ignore_limits) && $this->rest->ignore_limits = $row->ignore_limits;