sshpeer: add test showing that -q silences remote errors

Differential Revision: https://phab.mercurial-scm.org/D8583

tests/test-ssh.t

@@ -46,6 +46,9 b' repo not found error'
   remote: abort: repository nonexistent not found!
   abort: no suitable response from remote hg!
   [255]
+  $ hg clone -q -e "\"$PYTHON\" \"$TESTDIR/dummyssh\"" ssh://user@dummy/nonexistent local
+  abort: no suitable response from remote hg!
+  [255]
 
 non-existent absolute path
 
@@ -553,6 +556,7 b' debug output'
 
   $ cat dummylog
   Got arguments 1:user@dummy 2:hg -R nonexistent serve --stdio
+  Got arguments 1:user@dummy 2:hg -R nonexistent serve --stdio
   Got arguments 1:user@dummy 2:hg -R $TESTTMP/nonexistent serve --stdio
   Got arguments 1:user@dummy 2:hg -R remote serve --stdio
   Got arguments 1:user@dummy 2:hg -R local-stream serve --stdio (no-reposimplestore !)