buffer/settings: On filetype change remove the following steps

- reload runtime files
- reset globals
- parse the settings again

since this isn't the task of a filetype change.

internal/buffer/settings.go

@@ -26,15 +26,6 @@ func (b *Buffer) SetOptionNative(option string, nativeValue interface{}) error {
 	} else if option == "statusline" {
 		screen.Redraw()
 	} else if option == "filetype" {
-		config.InitRuntimeFiles(true)
-		err := config.ReadSettings()
-		if err != nil {
-			screen.TermMessage(err)
-		}
-		err = config.InitGlobalSettings()
-		if err != nil {
-			screen.TermMessage(err)
-		}
 		config.InitLocalSettings(b.Settings, b.Path)
 		b.UpdateRules()
 	} else if option == "fileformat" {