Fix comment on RtpVideoSender's ownership of Rtp modules.
Fix comment on RtpVideoSender's ownership of Rtp modules.

Followup to cl https://webrtc-review.googlesource.com/c/src/+/88240.

Bug: webrtc:9517
Change-Id: I51035f78c0930cd8ad1fd7d6036b184229078af3
Reviewed-on: https://webrtc-review.googlesource.com/93023
Reviewed-by: Sebastian Jansson <c24d1bc144eb7c11e553f59153fa17dba85ca83e@webrtc.org>
Commit-Queue: Niels Moller <0057859e47d61d90529d0f66d9ef692cefedb46a@webrtc.org>
Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#24229}
ShiftMediaProject/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc