Disable plugins and file access from the web view

This is probably not required here and good practise as a further hardening.

src/com/owncloud/android/ui/dialog/SamlWebViewDialog.java

@@ -158,7 +158,9 @@ public class SamlWebViewDialog extends DialogFragment {
             webSettings.setSupportZoom(true);
             webSettings.setBuiltInZoomControls(true);
             webSettings.setDisplayZoomControls(false);
-            
+            webSettings.setAllowFileAccess(false);
+            webSettings.setPluginsEnabled(false);
+
             CookieManager cookieManager = CookieManager.getInstance();
             cookieManager.setAcceptCookie(true);
             cookieManager.removeAllCookie();
@@ -273,4 +275,4 @@ public class SamlWebViewDialog extends DialogFragment {
         super.show(manager, tag);
     }
     
-}
+}