updates.redhat.com inconsistent

[Omer van der Horst Jansen <redhatlist vdhj com>]

The updates.redhat.com ftp servers don't seem to be properly 
synchronized with each other at the moment.

I have a local mirror for the 7.x versions (more efficient than 
updating 7 machines individually over a dialup link), and right now the 
php and libpng updates for 7.1 and 7.2 keep appearing and then 
disappearing on me.