Dialog: generating the request uri with alias when route header present

[surendratiwari3]

Pre-Submission Checklist

• Commit message has the format required by CONTRIBUTING guide
• Commits are split per component (core, individual modules, libs, utils, ...)
• Each component has a single commit (if not, squash them into one commit)
• No commits to README files for modules (changes must be done to docbook files
  in doc/ subfolder, the README file is autogenerated)

Type Of Change

• Small bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds new functionality)
• Breaking change (fix or feature that would change existing functionality)

Checklist:

• PR should be backported to stable branches
• Tested changes locally
• Related to issue when using terminate_dlg via xmlrpc, not able to generate proper bye message, if request is behind nat. #1689 (replace XXXX with an open issue number)

Description

Using contact as request uri when there is route header present in the dialog

[surendratiwari3]

@miconda please review.

[surendratiwari3]

closing this as this is incorporated by 810d849.