Improve the tooltips on the call lobby join button

Currently they display a redundant 'Join' tooltip on hover, and place the tooltip on the left. This removes the redundant tooltip and places the tooltip below the button, which looks a bit more balanced.

src/components/views/voip/CallView.tsx

@@ -246,9 +246,9 @@ export const Lobby: FC<LobbyProps> = ({ room, joinCallButtonDisabled, joinCallBu
             kind="primary"
             disabled={connecting || joinCallButtonDisabled}
             onClick={onConnectClick}
-            title={_t("Join")}
             label={_t("Join")}
             tooltip={connecting ? _t("Connecting") : joinCallButtonTooltip}
+            alignment={Alignment.Bottom}
         />
     </div>;
 };