Correctly remember tag unselection

The config is now updated both when a tag is selected and when
tags are unselected.

This fixes GitHub issue #1130

GTG/gtk/browser/sidebar.py

@@ -405,6 +405,7 @@ def tags_unbind_cb(self, signallistitem, listitem, user_data=None) -> None:
 
     def unselect_tags(self) -> None:
         """Clear tags selection"""
+        self.browser.config.set("selected_tag", '')
 
         with signal_block(self.tag_selection, self.tag_handle):
             self.tag_selection.unselect_all()
@@ -492,8 +493,6 @@ def on_tag_selected(self, model, position, n_items, user_data=None):
 
         if tags:
             self.browser.config.set("selected_tag", tags[0])
-        else:
-            self.browser.config.set("selected_tag", '')
 
         self.emit('selection_changed')