rtpengine: rebuild sockets if any skipped nodes

[smititelu]

Retry build_rtpp_socks() if any DNS or create, bind, connect
issues happened when kamailio started, and at least one node
from list was skipped.

This retry will happen automatically, when select_rtpp_node() is called
and will avoid a need for a "kamcmd rtpengine.reload"

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 #XXXX (replace XXXX with an open issue number)

Description

Described above.

[miconda]

@rfuchs - any comments on this PR?

[rfuchs]

@rfuchs - any comments on this PR?

LGTM 👍

[henningw]

Thanks for the review. It seems like a smaller change, merged.