Add assert for login/password

src/ldap-auth-request.lua

@@ -20,6 +20,8 @@ local decode_authorization = function(header)
     local auth_string_b64 = string.match(header, "^Basic%s([^%s]+)$")
     local auth_string, _ = mime.unb64(auth_string_b64)
     local login, password = string.match(auth_string, "^([^:]+)[:](.+)$")
+    assert(login ~= nil and login ~= "", [[Login empty!]])
+    assert(password ~= nil and password ~= "", [[Password empty!]])
     return login, password
 end