Update url_m_loc variable to the newly generated one in set-destination

[jasmine-nahrain]

When set-destination URL is called, it creates a new url_m_loc with the new url and assigns that to the buffer. The requestUrl is never updated therefore any subsequent set-destination call will use the incorrect url_m_loc. This change tracks if the url has been changed, if so it will get the url_m_loc from the http hdr which has the updated loc. This issue is also present in 9.2