Update manifest.json to add non-free option

manifest.json

@@ -73,6 +73,15 @@
                 "choices": ["fr", "en"],
                 "default": "en"
             }
+             {
+                "name": "accept_licence_non-free",
+		        "type": "boolean",
+                "ask": {
+                    "en": "This app can use non-free repo to install snmp-mibs-downloader package (help on OID resultion), do you want install this package ?",
+                    "fr": "Cette application peut utiliser le repo non-free pour installer snmp-mibs-downloader (qui aide à la résolution des OID), souhaitez vous installez ce packet ?"
+                },
+                "default": false
+            }
         ]
     }
 }