support/testing/tests/package/test_python_flask*: increase time after server startup

It seems like on Gitlab CI, the runners are quite slow, and the Flask
server does not startup in the 15 seconds we give it. So increase this
to 30 seconds before trying to contact the Flask server.

Hopefully fixes:

  https://gitlab.com/buildroot.org/buildroot/-/jobs/3249828594

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

support/testing/tests/package/test_python_flask.py

@@ -21,7 +21,7 @@ class TestPythonPy3Flask(TestPythonPackageBase):
         _, exit_code = self.emulator.run(cmd, timeout=self.timeout)
 
         # Give enough time for the flask server to start up
-        time.sleep(15)
+        time.sleep(30)
 
         cmd = "wget -q -O - http://127.0.0.1:5000/"
         output, exit_code = self.emulator.run(cmd, timeout=self.timeout)

support/testing/tests/package/test_python_flask_expects_json.py

@@ -31,7 +31,7 @@ class TestPythonPy3FlaskExpectsJson(TestPythonPackageBase):
         _, exit_code = self.emulator.run(cmd, timeout=self.timeout)
 
         # Give enough time for the flask server to start up
-        time.sleep(15)
+        time.sleep(30)
 
         self.try_json("""{"email": "test", "name": "test"}""", 200)
         self.try_json("""{"email": "test", "name": 2}""", 400)