Php 7.2 warning message fix on install.

[eileenmcnaughton]

Overview

Fixes a warning message when installing on php 7.2

Before

After

fixed

Technical Details

This declares errors and warnings as class properties to avoid
errors on counting them.

Also remove an unused return false as this is not consistent with the rest of the
function

Comments

[civibot]

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[totten]

Hrm, oops. Looks like this is concurrent with #13326 and addresses the same use-case. I saw that one first and merged because it seemed very simple.

This patch is actually better (it cleans up some older-style/less-clear code), and the patches are not mutually exclusive. But this one is slightly longer - so we might want to r-run it first.