Upgrade to rector 0.19 to fix phpstan incompatibility (#1211)

Author: GromNaN

composer.json

@@ -21,7 +21,7 @@
     },
     "require-dev": {
         "doctrine/coding-standard": "^12.0",
-        "rector/rector": "^0.18",
+        "rector/rector": "^0.19",
         "squizlabs/php_codesniffer": "^3.7",
         "symfony/phpunit-bridge": "^5.2",
         "vimeo/psalm": "^5.13"