winhttp/tests: Add a trailing '\n' to an ok() call.

dlls/winhttp/tests/winhttp.c

@@ -250,7 +250,7 @@ static void test_WinHttpAddHeaders(void)
     len = sizeof(buffer);
     ret = WinHttpQueryHeaders(request, WINHTTP_QUERY_CUSTOM | WINHTTP_QUERY_FLAG_REQUEST_HEADERS,
         test_header_name, buffer, &len, &index);
-    ok(ret == FALSE, "WinHttpQueryHeaders unexpectedly succeeded, found 'Warning' header.");
+    ok(ret == FALSE, "WinHttpQueryHeaders unexpectedly succeeded, found 'Warning' header.\n");
     ret = WinHttpAddRequestHeaders(request, test_headers[0], -1L, WINHTTP_ADDREQ_FLAG_ADD);
     ok(ret == TRUE, "WinHttpAddRequestHeader failed to add new header, got %d with error %u.\n", ret, GetLastError());