srt: Accepts URIs without host to go into listener mode

Just setting a URI without a hostname should directly go into listener mode.
8 jobs for 874-fix-no-host-uri in 15 minutes and 33 seconds (queued for 1 second)
Status Job ID Name Coverage
  Preparation
passed #88193
gst indent

00:00:35

passed #88192
manifest

00:00:35

 
  Build
passed #88194
build fedora x86_64

00:03:11

 
  Test
passed #88195
check fedora

00:03:16

 
  Full Builds
passed #88196
build android arm64 api28

00:03:32

passed #88198
build cerbero cross win32

00:08:29

passed #88199
build cerbero cross win64

00:06:07

passed #88197
build cerbero fedora x86_64

00:06:41