frontend_common: Use optional for language default

src/video_core/host1x/ffmpeg/ffmpeg.cpp

@@ -233,12 +233,7 @@ std::unique_ptr<Frame> DecoderContext::ReceiveFrame(bool* out_is_interlaced) {
             return false;
         }
 
-        *out_is_interlaced =
-#if defined(FF_API_INTERLACED_FRAME) || LIBAVUTIL_VERSION_MAJOR >= 59
-            (frame->flags & AV_FRAME_FLAG_INTERLACED) != 0;
-#else
-            frame->interlaced_frame != 0;
-#endif
+        *out_is_interlaced = frame->interlaced_frame != 0;
         return true;
     };
 

src/yuzu/configuration/qt_config.cpp

@@ -225,7 +225,8 @@ void QtConfig::ReadPathValues() {
     UISettings::values.recent_files =
         QString::fromStdString(ReadStringSetting(std::string("recentFiles")))
             .split(QStringLiteral(", "), Qt::SkipEmptyParts, Qt::CaseSensitive);
-    UISettings::values.language = ReadStringSetting(std::string("language"), std::string(""));
+    UISettings::values.language =
+        ReadStringSetting(std::string("language"), std::make_optional(std::string("")));
 
     EndGroup();
 }