allow connections to be closed before they even started, if some error coming from the parser requires it (can happen if user input is evaluated in httpx time and fails)

lib/httpx/connection.rb

@@ -448,7 +448,7 @@ module HTTPX
       end
       parser.on(:close) do |force|
         transition(:closing)
-        if force
+        if force || @state == :idle
           transition(:closed)
           emit(:close)
         end