fix: end a record with \n\r

sdp/sdp_test.go

@@ -32,7 +32,8 @@ a=rtpmap:122 telephone-event/32000
 a=fmtp:122 0-16
 a=ssrc:1204560450 cname:4585300731f880ff
 a=rtcp:57798 IN IP4 192.168.100.11
-a=rtcp-mux`
+a=rtcp-mux
+`
 
 	// Fails due to b=TIAS:64000
 	sd := SessionDescription{}

sdp/utils.go

@@ -98,6 +98,6 @@ func GenerateForAudio(originIP net.IP, connectionIP net.IP, rtpPort int, mode Mo
 	// 	fmt.Sprintf("a=rtcp:%d IN IP4 %s", rtpPort+1, connectionIP),
 	// }
 
-	res := strings.Join(s, "\r\n")
+	res := strings.Join(s, "\r\n") + "\r\n"
 	return []byte(res)
 }