Christian Weiske has posted a quick guide for those still dealing with PHP 4-style constructors in their code and how to upgrade them for PHP 7 (as it's completely deprecated now).

PHP 7 deprecates PHP4-style constructors. In PHP4, class constructor methods had the same name as the class. This was bad when switching base classes; you did not only have to change the class' extends declaration, but also calls to the parent constructor. PHP5 then introduced the generic __construct method name for class constructors, which solved the problem. ?

PHP7 will output a deprecation message when a class with a PHP4-style constructor is loaded

He suggests that a "quick fix" is to just rename the method to __construct and let PHP handle things as expected. However, dependencies in other classes (calling them in a PHP 4 way) could break because of this. He suggests a "real fix" that can be put in place until the remainder of the code is migrated - a method named the same as the old constructor but just calling __construct internally.