add message about processing completion (fix #8916)

Author: alexbruy

python/plugins/GdalTools/tools/doExtractProj.py

@@ -120,6 +120,7 @@ def updateProgress( self ):
 
   def processingFinished( self ):
     self.stopProcessing()
+    QMessageBox.information(self, self.tr( "Finished" ), self.tr( "Processing completed." ) )
 
   def processingInterrupted( self ):
     self.restoreGui()