Fix all SQL queries, to make sure they use pg_query_params for parameter injection.
Simplify various `if` conditionals to 1-liners.

Also use this for required $_GET parameters.

Instead of just including the config, it must be required, as it is an essential file.
Move require statement below $_GET checks.

Revert "Merge branch 'master' of https://github.com/MatrixCrawler/Poduptime into MatrixCrawler-master"

This reverts commit 4bfef977, reversing
changes made to b2666414.