[processing] Add a help string to tell users what they can do in the …

…history dialog

python/plugins/processing/gui/HistoryDialog.py

@@ -158,7 +158,8 @@ def executeAlgorithm(self):
     def changeText(self):
         item = self.tree.currentItem()
         if isinstance(item, TreeLogEntryItem):
-            self.text.setText(item.entry.text.replace(LOG_SEPARATOR, '\n'))
+            self.text.setText('"""\n' + self.tr('Double-click on the history item or paste the command below to re-run the algorithm') + '\n"""\n\n' +
+                              item.entry.text.replace('processing.run(', 'processing.execAlgorithmDialog(').replace(LOG_SEPARATOR, '\n'))
 
     def createTest(self):
         item = self.tree.currentItem()