Falsely highlighting of links in code blocks

@tim-gromeyer, unfortunately https://github.com/pbek/qmarkdowntextedit/commit/53c4c598 of https://github.com/pbek/qmarkdowntextedit/pull/188 did break something else too: ```markdown wget http://google.com ``` `http://google.com` is now highlighted as link, but it shouldn't. _Originally posted by @pbek in https://github.com/pbek/qmarkdowntextedit/issues/188#issuecomment-1839158353_