Add environment variable to allow insecure connections (self-signed certs)

NHEKO_ALLOW_INSECURE_CONNECTIONS=1 ./nheko

fixes #260

include/MatrixClient.h

@@ -102,7 +102,7 @@ public slots:
 
         void setServer(const QString &server)
         {
-                server_ = QUrl(QString("https://%1").arg(server));
+                server_ = QUrl(QString("%1://%2").arg(serverProtocol_).arg(server));
         };
         void setAccessToken(const QString &token) { token_ = token; };
         void setNextBatchToken(const QString &next_batch) { next_batch_ = next_batch; };
@@ -193,9 +193,10 @@ private:
         // Increasing transaction ID.
         int txn_id_;
 
-        // Token to be used for the next sync.
+        //! Token to be used for the next sync.
         QString next_batch_;
-
-        // filter to be send as filter-param for (initial) /sync requests
+        //! http or https (default).
+        QString serverProtocol_;
+        //! Filter to be send as filter-param for (initial) /sync requests.
         QString filter_;
 };

src/MatrixClient.cc

@@ -25,6 +25,7 @@
 #include <QNetworkReply>
 #include <QNetworkRequest>
 #include <QPixmap>
+#include <QProcessEnvironment>
 #include <QSettings>
 #include <QUrlQuery>
 #include <mtx/errors.hpp>
@@ -36,11 +37,26 @@ MatrixClient::MatrixClient(QString server, QObject *parent)
   : QNetworkAccessManager(parent)
   , clientApiUrl_{"/_matrix/client/r0"}
   , mediaApiUrl_{"/_matrix/media/r0"}
-  , server_{"https://" + server}
+  , serverProtocol_{"https"}
 {
         QSettings settings;
         txn_id_ = settings.value("client/transaction_id", 1).toInt();
 
+        auto env = QProcessEnvironment::systemEnvironment();
+
+        auto allowInsecureConnections = env.value("NHEKO_ALLOW_INSECURE_CONNECTIONS", "0");
+
+        if (allowInsecureConnections == "1") {
+                qWarning() << "Insecure connections are allowed: SSL errors will be ignored";
+                connect(
+                  this,
+                  &QNetworkAccessManager::sslErrors,
+                  this,
+                  [](QNetworkReply *reply, const QList<QSslError> &) { reply->ignoreSslErrors(); });
+        }
+
+        setServer(server);
+
         QJsonObject default_filter{
           {
             "room",