Replace boost::optional with std::optional (#4877)

src/providers/twitch/PubSubManager.hpp

@@ -5,7 +5,6 @@
 #include "util/ExponentialBackoff.hpp"
 #include "util/QStringHash.hpp"
 
-#include <boost/optional.hpp>
 #include <pajlada/signals/signal.hpp>
 #include <QJsonObject>
 #include <QString>
@@ -15,6 +14,7 @@
 #include <chrono>
 #include <map>
 #include <memory>
+#include <optional>
 #include <thread>
 #include <unordered_map>
 #include <vector>
@@ -188,7 +188,7 @@ private:
     void registerNonce(QString nonce, NonceInfo nonceInfo);
 
     // Find client associated with a nonce
-    boost::optional<NonceInfo> findNonceInfo(QString nonce);
+    std::optional<NonceInfo> findNonceInfo(QString nonce);
 
     std::unordered_map<QString, NonceInfo> nonces_;