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

src/singletons/Paths.hpp

@@ -1,8 +1,9 @@
 #pragma once
 
-#include <boost/optional.hpp>
 #include <QString>
 
+#include <optional>
+
 namespace chatterino {
 
 class Paths
@@ -51,7 +52,7 @@ private:
     void initRootDirectory();
     void initSubDirectories();
 
-    boost::optional<bool> portable_;
+    std::optional<bool> portable_;
 
     // Directory for cache files. Same as <appDataDirectory>/Misc
     QString cacheDirectory_;