Fixes a crash when the timestamp difference between two packets is zero, which can happen due to probing for example. Bug: none Change-Id: If04dfaed0b10aecd7b1a1e5487161c2d82ad9e44 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/338020 Commit-Queue: Jakob Ivarsson <jakobi@webrtc.org> Reviewed-by: Henrik Lundin <hlundin@google.com> Reviewed-by: Henrik Lundin <henrik.lundin@webrtc.org> Cr-Commit-Position: refs/heads/main@{#41669}