Make webkit-patch try harder to find keychain credentials

Make webkit-patch try harder to find keychain credentials
https://bugs.webkit.org/show_bug.cgi?id=140170

Reviewed by Ryosuke Niwa.

When the user manually enters a password into webkit-patch, we hand that off to the
Keyring Python module. However, that module creates a generic password entry instead
of an internet password entry. We should look for both kinds.

* Scripts/webkitpy/common/net/credentials.py:
(Credentials._run_security_tool):
(Credentials._credentials_from_keychain):
* Scripts/webkitpy/common/net/credentials_unittest.py:
(test_security_output_parse_entry_not_found):
(_assert_security_call):

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@178049 268f45cc-cd09-0410-ab3c-d52691b4dbfc