support/testing: fix python_flask_expect_python

Commit e6ee07f41a2b (package/python-flask-expects-json: new package)
added a non-functional test case that, as noticed by Edgar, fails with:

    AssertionError: '%{http_code}' != '200'

That's because the % sign is self-escaped, à-la C, in the first part
of the command, probably to avoid its being %-formatted. But only the
second part of the command is %-formatted, so we do not need to
self-escape % in the first part.

Additionally, since eb3ee3078a76 (support/testing/infra/emulator.py:
prevent the commands from wrapping), we no longer need to play tricks
with commands that are too long to fit on the first line of the shell
prompt.

Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Cc: Edgar Bonet <bonet@grenoble.cnrs.fr>
Reviewed-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>

support/testing/tests/package/test_python_flask_expects_json.py

@@ -17,11 +17,11 @@ class TestPythonPy3FlaskExpectsJson(TestPythonPackageBase):
     timeout = 60
 
     def try_json(self, payload, expects):
-        cmd = """curl -s -o /dev/null -w "%%{http_code}\\n" -X POST """
+        cmd = """curl -s -o /dev/null -w "%{http_code}\\n" -X POST """
         cmd += """-H "Content-Type: application/json" -d '%s' http://127.0.0.1:5000""" % payload
         output, exit_code = self.emulator.run(cmd, timeout=self.timeout)
         self.assertEqual(exit_code, 0)
-        self.assertEqual(output[-1], str(expects))
+        self.assertEqual(output[0], str(expects))
 
     def test_run(self):
         self.login()