Insure the web RootDirectory ends in a slash.

Reported by Compctech via DOVE-Net:

"On a side note,  I had to modify the letsyncrypt.js file to get letsencrypt to
work.  I had to add a / before .well-known on lines 86 - 89 & 96."

I'm guessing this is because his sbbs.ini [Web] RootDirectory wasn't terminated with a slash.

exec/letsyncrypt.js

@@ -177,7 +177,7 @@ var sysop_email = "sysop@" + system.inet_addr;
 /*
  * Now read the settings and state.
  */
-webroots[sbbsini.web.host_name] = sbbsini.web.root_dir;
+webroots[sbbsini.web.host_name] = backslash(sbbsini.web.root_dir);
 if (settings.open("r")) {
 	domain_list = settings.iniGetObject("Domains");
 	for (i in domain_list) {