removed obsolete property

WebContent/core/manifest.json

@@ -27,6 +27,5 @@
     "resources/icon_16.png"
   ],
   "permissions": [ "tabs", "http://*/*", "https://*/*", "unlimitedStorage" ],
-  "minimum_chrome_version" : "7",
   "manifest_version": 2
 }

WebContent/ui/manifest.json

@@ -30,7 +30,6 @@
     "pages/banner.css",
     "scripts/content/banner.js"
   ],
-  "permissions": [ "tabs", "notifications", "contextMenus" ],
-  "minimum_chrome_version" : "7",
+  "permissions": [ "tabs", "contextMenus" ],
   "manifest_version": 2
 }