Better curl debug (#165)

This PR makes it so the launcher logs curl's error description.

---

By creating this pull request, I understand that code that is AI
generated or otherwise automatically generated may be rejected without
further discussion.
I declare that I fully understand all code I pushed into this PR, and
wrote all this code myself and own the rights to this code.

src/Network/Http.cpp

@@ -73,14 +73,18 @@ std::string HTTP::Get(const std::string& IP) {
     static thread_local CURL* curl = curl_easy_init();
     if (curl) {
         CURLcode res;
+        char errbuf[CURL_ERROR_SIZE];
         curl_easy_setopt(curl, CURLOPT_URL, IP.c_str());
         curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, CurlWriteCallback);
         curl_easy_setopt(curl, CURLOPT_WRITEDATA, (void*)&Ret);
         curl_easy_setopt(curl, CURLOPT_CONNECTTIMEOUT, 10); // seconds
         curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L);
+        curl_easy_setopt(curl, CURLOPT_ERRORBUFFER, errbuf);
+        errbuf[0] = 0;
         res = curl_easy_perform(curl);
         if (res != CURLE_OK) {
             error("GET to " + IP + " failed: " + std::string(curl_easy_strerror(res)));
+            error("Curl error: " + std::string(errbuf));
             return "";
         }
     } else {
@@ -95,6 +99,7 @@ std::string HTTP::Post(const std::string& IP, const std::string& Fields) {
     static thread_local CURL* curl = curl_easy_init();
     if (curl) {
         CURLcode res;
+        char errbuf[CURL_ERROR_SIZE];
         curl_easy_setopt(curl, CURLOPT_URL, IP.c_str());
         curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, CurlWriteCallback);
         curl_easy_setopt(curl, CURLOPT_WRITEDATA, (void*)&Ret);
@@ -106,10 +111,13 @@ std::string HTTP::Post(const std::string& IP, const std::string& Fields) {
         curl_easy_setopt(curl, CURLOPT_HTTPHEADER, list);
         curl_easy_setopt(curl, CURLOPT_CONNECTTIMEOUT, 10); // seconds
         curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L);
+        curl_easy_setopt(curl, CURLOPT_ERRORBUFFER, errbuf);
+        errbuf[0] = 0;
         res = curl_easy_perform(curl);
         curl_slist_free_all(list);
         if (res != CURLE_OK) {
             error("POST to " + IP + " failed: " + std::string(curl_easy_strerror(res)));
+            error("Curl error: " + std::string(errbuf));
             return "";
         }
     } else {