Update DatabaseSessionHandler.php

tlaverdure/laravel-echo-server#546
When request doesn't has `ipAddress` or 'User-Agent' don't overwrite the last one

Author: PaolaRuby

src/Illuminate/Session/DatabaseSessionHandler.php

@@ -233,11 +233,13 @@ protected function userId()
      */
     protected function addRequestInformation(&$payload)
     {
-        if ($this->container->bound('request')) {
-            $payload = array_merge($payload, [
-                'ip_address' => $this->ipAddress(),
-                'user_agent' => $this->userAgent(),
-            ]);
+        if (! $this->container->bound('request')) {
+            if ($this->ipAddress()) {
+                $payload['ip_address'] = $this->ipAddress();
+            }
+            if ($this->userAgent()) {
+                $payload['user_agent'] = $this->userAgent();
+            }
         }
 
         return $this;