rtp: opuspay: fix memory leak in gst_rtp_opus_pay_setcaps.

The src caps were never dereferenced, causing a memory leak.
21 jobs for rtp_opuspay_memleak_fix in 48 minutes and 12 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Preparation
passed #436617
gst indent

00:00:30

passed #436616
manifest

00:00:22

 
  Build
passed #436623
build cerbero android universal

00:13:05

passed #436624
build cerbero cross win32

00:12:38

passed #436625
build cerbero cross win64

00:05:09

passed #436622
build cerbero fedora x86_64

00:11:10

manual #436627
gst-ios-12.2 allowed to fail manual
build cerbero ios universal
passed #436626
gst-macos-10.14
build cerbero macos x86_64

00:09:11

passed #436618
build fedora x86_64

00:11:57

passed #436619
build nodebug fedora x86_64

00:10:31

passed #436620
build static fedora x86_64

00:11:30

passed #436621
build static nodebug fedora x86_64

00:14:38

 
  Test
passed #436650
check fedora

00:04:13

passed #436629
integration testsuites fedora

00:10:46

passed #436631
valgrind bad

00:06:19

passed #436632
valgrind ges

00:05:19

passed #436649
valgrind good

00:14:31

failed #436628
check fedora

00:04:52

failed #436630
valgrind good

00:14:37

 
  Integrate
passed #436633
android universal examples

00:07:44

passed #436634
documentation

00:05:05