rtsp-client: RTP Info when completed_sender

Change condition that should be fulfilled regarding RTPInfo.
Replace !gst_rtsp_media_is_receive_only with
gst_rtsp_media_has_completed_sender. It is more correct to actually look
for a sender pipeline that is complete. Only then a RTPInfo should
exist.

gst_rtsp_media_is_receive_only gives different answears depending on
state of server.
If Describe is called wth URL+options for backchannel SDP will give only
audio and only backchannel a=sendonly
If Describe is called on URL+options that gives both audio and video
direction from server to client, pipelines are created. Thus
receive_only will return false, even though Setup only would setup
backchannel.

RTP-Info is only for outgoing streams. Thus one should look if outgoing
streams are complete.
Status Job ID Name Coverage
  Preparation
passed #685155
gst indent

00:00:28

passed #685154
manifest

00:00:34

 
  Build
passed #685165
build cerbero cross-android universal

00:11:11

manual #685169
gst-ios-12.2 allowed to fail manual
build cerbero cross-ios universal
passed #685166
build cerbero cross win32

00:08:22

passed #685167
build cerbero cross win64

00:06:08

passed #685164
build cerbero fedora x86_64

00:08:39

passed #685168
gst-macos-10.14
build cerbero macos x86_64

00:08:53

passed #685160
build clang fedora x86_64

00:06:32

passed #685156
build fedora x86_64

00:06:12

passed #685163
docker windows 1607
build msys2

00:12:40

passed #685157
build nodebug fedora x86_64

00:05:08

passed #685158
build static fedora x86_64

00:14:13

passed #685159
build static nodebug fedora x86_64

00:04:48

passed #685161
docker windows 1607
build vs2017 amd64

00:12:35

passed #685162
docker windows 1607
build vs2017 x86

00:11:15

 
  Test
passed #685170
check fedora

00:04:03

passed #686858
integration testsuites fedora

00:41:08

failed #685171
integration testsuites fedora

01:00:01

 
  Integrate
passed #685172
cross-android universal examples

00:07:59

manual #685174
gst-ios-12.2 allowed to fail manual
cross-ios universal examples
passed #685173
documentation

00:04:07