Improved documentation (thx @margaretha)

Change-Id: Ia6ccedabde4edbc5219c0e882d3e271e0b9dc6cb
diff --git a/t/script/extract.t b/t/script/extract.t
index 6c689f9..8dc2b98 100644
--- a/t/script/extract.t
+++ b/t/script/extract.t
@@ -31,7 +31,7 @@
   sub {
     system($call);
   },
-  qr!extract.+?Extracts KorAP-XML files!s,
+  qr!extract.+?\$ korapxml2krill!s,
   $call
 );