UI bug fixes.

- change popup title
- refresh popup url instead of closing and reopening the popup
-
Remove variable duplicate.
Fix app missing page flakiness.
Move updatePopupUrl to ChromeBrowserApi.
Remove extra space.
Merge pull request #714 from uProxy/lucyhe-update_popup_url

UI bug fixes.
Merge branch 'dev' of https://github.com/uProxy/uproxy into chrome-reload