[processing] Expand 'algorithm' group in history on load

Since all the useful stuff is in that group, you ALWAYS need
to expand it anyway!

python/plugins/processing/gui/HistoryDialog.py

@@ -106,6 +106,7 @@ class HistoryDialog(BASE, WIDGET):
             item.setIcon(0, self.keyIcon)
             groupItem.insertChild(0, item)
         self.tree.addTopLevelItem(groupItem)
+        groupItem.setExpanded(True)
 
     def executeAlgorithm(self):
         item = self.tree.currentItem()