Log Message:
py-qt4: updated to 4.12.3

v4.12.3:
- This is planned to be the last ever release of PyQt4.
- Bug fixes.

v4.12.2:
- A private copy of the sip module called PyQt4.sip is required.
- SIP v4.19.12 is now required.  SIP v5 is not supported.

Pkgsrc:
- Correct distinfo for x11 and mac.