fixup! remote/client: replace manual place checks with helper method …

…calls

Update expected error in test.

tests/test_client.py

@@ -248,7 +248,7 @@ def test_place_add_no_name(coordinator):
 
 def test_place_del_no_name(coordinator):
     with pexpect.spawn('python -m labgrid.remote.client delete') as spawn:
-        spawn.expect("name was not a string")
+        spawn.expect("place pattern not specified")
         spawn.expect(pexpect.EOF)
         spawn.close()
         assert spawn.exitstatus != 0, spawn.before.strip()