show plugin dependencies

gui/qt/main_window.py

@@ -2715,7 +2715,10 @@ class ElectrumWindow(QMainWindow):
                 else:
                     w = None
                 cb.clicked.connect(mk_toggle(cb, name, w))
-                grid.addWidget(HelpButton(descr['description']), i, 2)
+                msg = descr['description']
+                if descr.get('requires'):
+                    msg += '\n\n' + _('Requires') + ':\n' + '\n'.join(map(lambda x: x[1], descr.get('requires')))
+                grid.addWidget(HelpButton(msg), i, 2)
             except Exception:
                 print_msg("Error: cannot display plugin", name)
                 traceback.print_exc(file=sys.stdout)