[index.php] Filter parameter '_error_time' from queries
[index.php] Filter parameter '_error_time' from queries

The parameter is used in error feeds. Since RSS-Bridge returns valid
feeds for error conditions, feed readers may attempt to access the
URI returned for the feed item in order to collect additional data,
thus including the parameter '_error_time' in the query.

This results in another error message, because it is an invalid input
parameter. Filtering the parameter allows RSS-Bridge to return the
original feed.

References #882

kranack/rss-bridge,ORelio/rss-bridge,kranack/rss-bridge,RSS-Bridge/rss-bridge,Riduidel/rss-bridge,simonbru/rss-bridge,RSS-Bridge/rss-bridge,Frenzie/rss-bridge,RSS-Bridge/rss-bridge,sebsauvage/rss-bridge,ORelio/rss-bridge,Riduidel/rss-bridge,ORelio/rss-bridge,kranack/rss-bridge,Riduidel/rss-bridge,simonbru/rss-bridge,kranack/rss-bridge,Frenzie/rss-bridge