Fix file deletion

CHDataManagement/Model/Settings/PageSettings.swift

@@ -57,6 +57,24 @@ final class PageSettings: ObservableObject {
               german: german.file,
               english: english.file)
     }
+
+    func remove(_ file: FileResource) {
+        if codeHighlightingJsFile == file {
+            codeHighlightingJsFile = nil
+        }
+        if modelViewerJsFile == file {
+            modelViewerJsFile = nil
+        }
+        if defaultCssFile == file {
+            defaultCssFile = nil
+        }
+        if imageCompareJsFile == file {
+            imageCompareJsFile = nil
+        }
+        if imageCompareCssFile == file {
+            imageCompareCssFile = nil
+        }
+    }
 }
 
 extension PageSettings: LocalizedItem {