Bump minimum version of Netgen Open Graph bundle again

Author: RandyCupic

composer.json

@@ -34,7 +34,7 @@
     },
     "require-dev": {
         "ezsystems/legacy-bridge": "^2.0",
-        "netgen/open-graph-bundle": "^1.1.4",
+        "netgen/open-graph-bundle": "^1.2",
         "netgen/admin-ui-bundle": "^2.0",
         "matthiasnoback/symfony-dependency-injection-test": "^3.0",
         "mikey179/vfsstream": "^1.0",