[fix] fix gui error if multiple clicks on next button in connection_cfg by pubkey

Disabled button when clicked

src/sakia/gui/dialogs/connection_cfg/controller.py

@@ -358,6 +358,7 @@ The publication of this document will remove your identity from the network.</p>
     async def check_pubkey(self, checked=False):
         self._logger.debug("Is valid ? ")
         self.view.display_info(self.tr("connecting..."))
+        self.view.button_next.setDisabled(True)
         try:
             self.model.set_pubkey(self.view.edit_pubkey.text(), self.view.scrypt_params)
             self.model.set_uid(self.view.edit_uid.text())