t9003: become resilient to GETTEXT_POISON

The test t9003-help-autocorrect.sh fails when run under GETTEXT_POISON,
because it's expecting to filter out the original output. Accommodate
gettext poison case by also filtering out the default simulated output.

Signed-off-by: Vasco Almeida <vascomalmeida@sapo.pt>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t9003-help-autocorrect.sh

@@ -31,10 +31,10 @@ test_expect_success 'autocorrect showing candidates' '
 	git config help.autocorrect 0 &&
 
 	test_must_fail git lfg 2>actual &&
-	sed -e "1,/^Did you mean this/d" actual | grep lgf &&
+	grep "^	lgf" actual &&
 
 	test_must_fail git distimdist 2>actual &&
-	sed -e "1,/^Did you mean this/d" actual | grep distimdistim
+	grep "^	distimdistim" actual
 '
 
 test_expect_success 'autocorrect running commands' '