always position selection in center after search

https://anki.tenderapp.com/discussions/beta-testing/1888-retaining-position-when-searching

qt/aqt/browser.py

@@ -261,8 +261,6 @@ class DataModel(QAbstractTableModel):
         tv = self.browser.form.tableView
         if idx:
             tv.selectRow(idx.row())
-            # scroll if the selection count has changed
-            if count != len(self.selectedCards):
             # we save and then restore the horizontal scroll position because
             # scrollTo() also scrolls horizontally which is confusing
             h = tv.horizontalScrollBar().value()