Bad regex causing very slow execution

[kduffie]

If you attempt to run unfluff on the body of the following webpage, https://craftsbyamanda.com/vibrant-button-tree-on-canvas-a-giveaway/ you'll see that it takes more than 10secs on a fast Mac.

The problem has been isolated to line 22 of lib/extractor.js which takes around 10s to execute when operating on the contents of that particular webpage:

copyright = text.replace(/.*?©(\s*copyright)?([^,;:.|\r\n]+).*/gi, '$2').trim();