Minor fix for FlexUser, changelog update

CHANGELOG.md

@@ -2,6 +2,7 @@
 ## mm/dd/2019
 
 1. [](#new)
+    * Added phpstan: PHP Static Analysis Tool [#2393](https://github.com/getgrav/grav/pull/2393)
     * Grav 1.6: Renamed `$grav['users']` service to `$grav['accounts']`
     * Added `Flex::getObjects()` and `Flex::getMixedCollection()` methods for co-mingled collections
     * Added support to use single Flex key parameter in `Flex::getObject()` method
@@ -21,6 +22,7 @@
     * Fixed `Obtaining write lock failed on file...`
     * Fixed potential undefined property in `onPageNotFound` event handling
     * Grav 1.6: Fixed settion caching in `FlexIndex`
+    * Fixed some potential issues found by phpstan
 
 # v1.6.0-rc.3
 ## 02/18/2019

system/src/Grav/Common/User/FlexUser/User.php

@@ -60,7 +60,7 @@ class User extends FlexObject implements UserInterface, MediaManipulationInterfa
     /**
      * @var FileInterface|null
      */
-    protected $storage;
+    protected $_storage;
 
     /**
      * @return array
@@ -405,10 +405,10 @@ class User extends FlexObject implements UserInterface, MediaManipulationInterfa
     public function file(FileInterface $storage = null)
     {
         if (null !== $storage) {
-            $this->storage = $storage;
+            $this->_storage = $storage;
         }
 
-        return $this->storage;
+        return $this->_storage;
     }
 
     public function isValid(): bool

system/src/Grav/Framework/Form/FormFlash.php

@@ -32,7 +32,7 @@ class FormFlash implements \JsonSerializable
     protected $files;
     /** @var array */
     protected $uploadedFiles;
-    /** @var array<string, mixed> */
+    /** @var string[] */
     protected $uploadObjects;
     /** @var bool */
     protected $exists;