Don't reimplement ThumbCreator::flags()

It does the same thing as the default implementation

kcms/kfontinst/thumbnail/FontThumbnail.cpp

@@ -85,10 +85,4 @@ bool CFontThumbnail::create(const QString &path, int width, int height, QImage &
     delete tempDir;
     return !img.isNull();
 }
-
-ThumbCreator::Flags CFontThumbnail::flags() const
-{
-    return None;
-}
-
 }

kcms/kfontinst/thumbnail/FontThumbnail.h

@@ -20,7 +20,6 @@ public:
     }
 
     bool create(const QString &path, int width, int height, QImage &img) override;
-    Flags flags() const override;
 
 private:
     CFcEngine m_engine;