Fix bugs

Fix when no custom ruleset is set in external config file, no rules will be generated.
Fix ws-path parsing for Quantumult X VMess subscription.
Add README for Docker.
Optimize codes.

README-docker.md

@@ -0,0 +1,19 @@
+# subconverter-docker
+------
+This is a minimized image to run https://github.com/tindy2013/subconverter.
+
+For running this docker, simply use the following commands:
+```bash
+# run the container detached, forward internal port 25500 to host port 25500
+docker run -d -p 25500:25500 tindy2013/subconverter:latest
+# then check its status
+curl http://localhost:25500
+# if you see `subconverter vx.x.x backend` then the container is up and running
+```
+
+If you want to update `pref.ini` inside the docker, you can use the following command:
+```bash
+# assume your configuration file name is `newpref.ini`
+curl -F "@data=newpref.ini" http://localhost:25500/updateconf?type=form&token=password
+# you may want to change this token in your configuration file
+```

src/main.cpp

@@ -268,7 +268,7 @@ struct ExternalConfig
     std::string surge_rule_base;
     std::string surfboard_rule_base;
     std::string mellow_rule_base;
-    bool overwrite_original_rules = true;
+    bool overwrite_original_rules = false;
     bool enable_rule_generator = true;
 };
 
@@ -408,6 +408,12 @@ std::string subconverter(RESPONSE_CALLBACK_ARGS)
             extra_ruleset = extconf.surge_ruleset;
             refreshRulesets(extra_ruleset, rca);
         }
+        else
+        {
+            if(update_ruleset_on_request || cfw_child_process)
+                refreshRulesets(rulesets, ruleset_content_array);
+            rca = ruleset_content_array;
+        }
     }
     else
     {

src/speedtestutil.cpp

@@ -1366,6 +1366,8 @@ bool explodeSurge(std::string surge, std::string custom_port, int local_port, st
                 }
                 else if(itemName == "obfs-host")
                     host = itemVal;
+                else if(itemName == "obfs-uri")
+                    path = itemVal;
                 else if(itemName == "over-tls")
                     tls = itemVal == "true" ? "tls" : "";
             }

src/subexport.cpp

@@ -67,6 +67,8 @@ std::string vmessConstruct(std::string add, std::string port, std::string type,
         path = "/";
     if(!host.size())
         host = add;
+    if(!id.size())
+        id = "00000000-0000-0000-0000-000000000000"; //fill this field for node with empty id
     rapidjson::StringBuffer sb;
     rapidjson::Writer<rapidjson::StringBuffer> writer(sb);
     writer.StartObject();