rtpjitterbuffer: reset skew does not reset clock-rate
rtpjitterbuffer: reset skew does not reset clock-rate

Don't reset the clock-rate when we reset the skew correction algorithm.
Reset the skew correction algorithm when we change the clock-rate.

jhodapp/gst-plugins-good,jhodapp/gst-plugins-good,jhodapp/gst-plugins-good,jhodapp/gst-plugins-good