support/testing: TestCheckPackage: update expected strings

Commit dfed5acb56 ("utils/check-package: use https for the manual URL")
replaced the default url to the Buildroot manual while it was used
by TestCheckPackage test.

Update TestCheckPackage with https url.

Fixes:
https://gitlab.com/buildroot.org/buildroot/-/jobs/6224243484

Cc: Yann E. MORIN <yann.morin.1998@free.fr>
Signed-off-by: Romain Naour <romain.naour@smile.fr>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
(cherry picked from commit a9990552eb8b88647104bbec82555b2c407aa6be)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

support/testing/tests/utils/test_check_package.py

@@ -200,13 +200,13 @@ class TestCheckPackage(unittest.TestCase):
                            self.WITH_UTILS_IN_PATH, abs_path)
         self.assert_file_was_processed(m)
         self.assert_warnings_generated_for_file(m)
-        self.assertIn("{}:1: should be 80 hashes (http://nightly.buildroot.org/#writing-rules-mk)".format(rel_file), w)
+        self.assertIn("{}:1: should be 80 hashes (https://nightly.buildroot.org/#writing-rules-mk)".format(rel_file), w)
 
         w, m = call_script(["check-package", "-b", abs_file],
                            self.WITH_UTILS_IN_PATH, infra.basepath())
         self.assert_file_was_processed(m)
         self.assert_warnings_generated_for_file(m)
-        self.assertIn("{}:1: should be 80 hashes (http://nightly.buildroot.org/#writing-rules-mk)".format(abs_file), w)
+        self.assertIn("{}:1: should be 80 hashes (https://nightly.buildroot.org/#writing-rules-mk)".format(abs_file), w)
 
         # br2-external with ignore list
         topdir_path = infra.filepath("tests/utils/br2-external")