Add missing patch chunk

Add missing patch chunk

Remove fprintf causing log spam (SIPp#669)

Since SIPp#521, prepare_pkts may be called
on every call, not just on startup. This means that the log it prints to
stderr is very visible and may cause performance problems. This commit
removes it.

Allow build to proceed if gtest is missing (SIPp#638)

* Allow build to proceed if gtest is missing

* Commit changes file

Update CHANGES.md for 3.7.0 (SIPp#624)

v3.7.0~rc1

v3.6.2~rc1