sslutil: stop checking for web.cacerts=! (BC) The previous patch stopped setting web.cacerts=! to indicate --insecure. That left user configs as the only source that could introduce web.cacerts=!. The practical impact of this patch is we no longer honor web.cacerts=! in configs. Instead, we always treat web.cacerts as a path. The patch is therefore technically BC. However, since I don't believe web.cacerts=! is documented, it should be safe to remove. a939f08fae9c (which introduced --insecure) has no indication that web.cacerts=! is anything but an implementation detail, reinforcing my belief it can be removed without major debate.