fix for co2 emission input field in options page

Description of bug: the input field of CO2 emission rate of 0.255384 hardcoded in the html file, hence when the page first opens u see this value instead of the value saved by the user(if it is saved), the saved value is shown after a 1 sec delay resulting in "Strange Loading of Carbon Emission Rate in the Options page" issue: #113 (closed) solution: simply loaded the default value from options.js just before saved value is loaded and removed the hardcoded value from html file.