Fix incorrect extension for custom screenshot file name (fixes #337)

src/main/java/com/replaymod/extras/advancedscreenshots/GuiCreateScreenshot.java

@@ -95,6 +95,11 @@ public class GuiCreateScreenshot extends GuiRenderSettings implements Loadable {
         }
     }
 
+    @Override
+    public void load(RenderSettings settings) {
+        super.load(settings.withEncodingPreset(RenderSettings.EncodingPreset.PNG));
+    }
+
     @Override
     protected Path getSettingsPath() {
         return getMinecraft().runDirectory.toPath().resolve("config/replaymod-screenshotsettings.json");

src/main/java/com/replaymod/render/RenderSettings.java

@@ -206,6 +206,30 @@ public class RenderSettings {
         this.highPerformance = highPerformance;
     }
 
+    public RenderSettings withEncodingPreset(EncodingPreset encodingPreset) {
+        return new RenderSettings(
+                renderMethod,
+                encodingPreset,
+                videoWidth,
+                videoHeight,
+                framesPerSecond,
+                bitRate,
+                outputFile,
+                renderNameTags,
+                stabilizeYaw,
+                stabilizePitch,
+                stabilizeRoll,
+                chromaKeyingColor,
+                sphericalFovX,
+                sphericalFovY,
+                injectSphericalMetadata,
+                antiAliasing,
+                exportCommand,
+                exportArguments,
+                highPerformance
+        );
+    }
+
     /**
      * @return the width of the output video during rendering, including the upscale for Anti-Aliasing.
      */