Merge pull request #7301 from berendt/check_against_lowered_sha256sum

[get_url] check against lowered stripped sha256sum

library/network/get_url

@@ -283,7 +283,7 @@ def main():
         else:
             destination_checksum = module.sha256(dest)
 
-        if stripped_sha256sum != destination_checksum:
+        if stripped_sha256sum.lower() != destination_checksum:
             os.remove(dest)
             module.fail_json(msg="The SHA-256 checksum for %s did not match %s; it was %s." % (dest, sha256sum, destination_checksum))