fix typo

Author: nicolas-grekas

composer.json

@@ -28,7 +28,7 @@
         "symfony/config": "^4.2",
         "symfony/dependency-injection": "~3.4|~4.0",
         "symfony/form": "~4.3",
-        "symfony/http-kernel": "^4.3.7|~4.0",
+        "symfony/http-kernel": "^4.3.7",
         "symfony/messenger": "~4.3",
         "symfony/property-access": "~3.4|~4.0",
         "symfony/property-info": "~3.4|~4.0",