allow proxy channels to properly reset when trapped in proxy connection protocols

lib/httpx/plugins/proxy.rb

@@ -132,6 +132,13 @@ module HTTPX
         consume
       end
     end
+
+    def reset
+      @state = :open
+      transition(:closing)
+      transition(:closed)
+      emit(:close)
+    end
   end
 
   class ProxySSL < SSL

lib/httpx/plugins/proxy/socks4.rb

@@ -53,8 +53,6 @@ module HTTPX
             super
           end
 
-          private
-
           def on_socks_error(message)
             ex = Error.new(message)
             ex.set_backtrace(caller)