tests: stabilize test 1034

Pass the invalid domain name on stdin. On some systems, the test
framework cannot pass invalid UTF-8 sequences on the command line.

Closes #1488

tests/data/test1034

@@ -6,6 +6,7 @@ HTTP GET
 HTTP proxy
 IDN
 FAILURE
+config file
 </keywords>
 </info>
 
@@ -44,8 +45,11 @@ HTTP over proxy with malformatted IDN host name
 
 # This host name contains an invalid UTF-8 byte sequence that can't be
 # converted into an IDN name
+<stdin>
+url = "http://invalid-utf8-â<>.local/page/1034"
+</stdin>
  <command>
-http://invalid-utf8-â<>.local/page/1034 -x %HOSTIP:%HTTPPORT
+-K - -x %HOSTIP:%HTTPPORT
 </command>
 </client>