Read the config.php file only once

[bramley]

Currently the config.php file can be read more than once, which causes php notices about multiple definitions, e.g.

 PHP Notice: Constant UPLOADIMAGES_DIR already defined in /opt/lampp/htdocs/tiedotteet/config/config.php on line 28

This can cause the response to the browser to be corrupted when display errors is enabled. This was reported in the user forum https://discuss.phplist.org/t/automatic-update-from-3-6-2-to-3-6-3-fails/7546 and a GitHub issue phpList/phplist3#783

This change is to read config.php once in the constructor and store the few settings that are needed.

A second commit is to correct the handling of the result of PDO fetch() to avoid another php warning.

PHP Notice: Undefined index: update_in_progress in /opt/lampp/htdocs/tiedotteet/updater/index.php on line 360

Currently the wrong column name is being referenced.

[michield]

You could also just change all "include" lines to "include_once"

[bramley]

Currently the include statements are within functions, which means that the variables are visible only within the function. Using include_once would mean that the variables would not exist for the second and subsequent calls.

We could move the include statement to be at global scope, outside of the class. Doing that though would need changing the code to refer to the global variables instead of the local variables, so a similar number of changes to this one.

[michield]

Ah, true, it's all in the scope, makes sense.