default webroot in config, webroot in automatic redirect instead of request path

contrib/i2pd.conf

@@ -93,6 +93,8 @@ ipv6 = false
 ## Address and port service will listen on
 address = 127.0.0.1
 port = 7070
+## Path to web console, default "/"
+# webroot = /
 ## Uncomment following lines to enable Web Console authentication 
 # auth = true
 # user = i2pd