fix some basic type issues:

use size_t for size as async web server uses this type internally
use uint8_t for provision mode, we only have 3 values
address warnings about ordering initializers

src/APSettingsService.h

@@ -37,7 +37,7 @@ class APSettingsService : public SettingsService {
   private:
 
     // access point settings
-    int _provisionMode;
+    uint8_t _provisionMode;
     String _ssid;
     String _password;
 

src/AsyncJsonCallbackResponse.h

@@ -21,7 +21,7 @@ class AsyncJsonCallbackResponse: public AsyncJsonResponse {
 
   public:
 
-    AsyncJsonCallbackResponse(AsyncJsonCallback callback, bool isArray=false) : _callback{callback}, AsyncJsonResponse(isArray) {}
+    AsyncJsonCallbackResponse(AsyncJsonCallback callback, bool isArray=false) : AsyncJsonResponse(isArray), _callback{callback} {}
     ~AsyncJsonCallbackResponse() {
       _callback();
     }

src/AsyncJsonRequestWebHandler.h

@@ -22,7 +22,7 @@ class AsyncJsonRequestWebHandler: public AsyncWebHandler {
     String _uri;
     WebRequestMethodComposite _method;
     JsonRequestCallback _onRequest;
-    int _maxContentLength;
+    size_t _maxContentLength;
 
   public:
 
@@ -36,7 +36,7 @@ class AsyncJsonRequestWebHandler: public AsyncWebHandler {
 
     void setUri(const String& uri) { _uri = uri; }
     void setMethod(WebRequestMethodComposite method) { _method = method; }
-    void setMaxContentLength(int maxContentLength) { _maxContentLength = maxContentLength; }
+    void setMaxContentLength(size_t maxContentLength) { _maxContentLength = maxContentLength; }
     void onRequest(JsonRequestCallback fn) { _onRequest = fn; }
 
     virtual bool canHandle(AsyncWebServerRequest *request) override final {

src/SettingsService.h

@@ -122,7 +122,7 @@ private:
   public:
 
     SettingsService(AsyncWebServer* server, FS* fs, char const* servicePath, char const* filePath):
-    _server(server), _fs(fs), _filePath(filePath) {
+    _filePath(filePath), _server(server), _fs(fs){
 
       // configure fetch config handler
       _server->on(servicePath, HTTP_GET, std::bind(&SettingsService::fetchConfig, this, std::placeholders::_1));