Use SDCard usage where available

When an SD Card is available it is the more interesing
metric in terms of space usage. We are therefore using
it here.

Signed-off-by: Mimoja <git@mimoja.de>

ESP32_AP-Flasher/include/storage.h

@@ -26,6 +26,7 @@ class DynStorage {
     DynStorage();
     void begin();
     void listFiles();
+    size_t freeSpace();
 
    private:
     bool isInited;

ESP32_AP-Flasher/src/storage.cpp

@@ -44,8 +44,13 @@ static void initSDCard() {
 }
 #endif
 
-void copyToSD(FS &sourceFS, const char* source_path){
-    File root = sourceFS.open(source_path);
+size_t DynStorage::freeSpace(){
+    this->begin();
+#ifdef HAS_SDCARD
+    return SD.totalBytes() - SD.usedBytes();
+#endif
+    return LittleFS.totalBytes() - LittleFS.usedBytes();
+}
 
 void copyFile(File in, File out) {
     Serial.print("Copying ");

ESP32_AP-Flasher/src/web.cpp

@@ -136,7 +136,7 @@ void wsSendSysteminfo() {
     sys["heap"] = ESP.getFreeHeap();
     sys["recordcount"] = tagDB.size();
     sys["dbsize"] = tagDB.size() * sizeof(tagRecord);
-    sys["littlefsfree"] = LittleFS.totalBytes() - LittleFS.usedBytes();
+    sys["littlefsfree"] = Storage.freeSpace();
     sys["apstate"] = apInfo.state;
     sys["runstate"] = config.runStatus;