net/py-ldappool: Update to 2.4.1

• Separate USES block from non-relevant variables.

• While I'm here: Add "do-test" target to make future QA easier.

Notable changes since 2.2.0:

• Allow pool status to be printed as a table
• Handle retry logic for timeouts with multiple LDAP servers
• Improve connection retry logging
• Fix ldappool bad password retry logic

PR: 246402
Submitted by: sunpoet
MFH: 2020Q2 (Blanket: Bug/Reliability fixes)