Don't log errors from callng close on OR conns

Snowflake copies data between the OR connection and the KCP stream,
meaning that in most cases the copy loops will only terminate once the
OR connection times out. In this case the OR connection is already
closed and so calls to CloseRead and CloseWrite will generate errors.
4 jobs for master in 5 minutes and 27 seconds (queued for 1 minute and 31 seconds)
Status Job ID Name Coverage
  Test
failed #15813
android

00:05:27

passed #15816
debian-testing

00:02:56

passed #15814
go-1.13

00:01:26

passed #15815
go-1.14

00:02:51

 
Name Stage Failure
failed
android Test
fmt
log
gomobile: go build -v -buildmode=c-shared -o=/tmp/gomobile-work-927209075/android/src/main/jniLibs/armeabi-v7a/libgojni.so ./gobind failed: exit status 2

Running after_script
Running after script...
$ echo "Download debug artifacts from https://gitlab.com/${CI_PROJECT_PATH}/-/jobs"
Download debug artifacts from https://gitlab.com/tpo/anti-censorship/pluggable-transports/snowflake/-/jobs
ERROR: Job failed: exit code 1