Fix thumbnail size request

Can't use 0 size or negatives, so use the maximum positive value, when
one diemension is invalid.

src/mxcimageprovider.cpp

@@ -26,8 +26,8 @@ void MXCImageResponse::run() {
 
         mtx::http::ThumbOpts opts;
         opts.mxc_url = "mxc://" + m_id.toStdString();
-        opts.width = m_requestedSize.width();
-        opts.height = m_requestedSize.height();
+        opts.width = m_requestedSize.width() > 0 ? m_requestedSize.width() : -1;
+        opts.height = m_requestedSize.height() > 0 ? m_requestedSize.height() : -1;
         opts.method = "scale";
         http::client().get_thumbnail(opts, [this, cacheFile](const std::string &res, mtx::http::RequestErr err) {
             if (err) {

src/pch/mtx-pch.h

+#pragma once
+
+#include <mtx.hpp>
+#include <mtxclient/http/client.hpp>