Don't hardcode ConfirmUserActionDialog title

Signed-off-by: Stefan Parviainen <pafcu@iki.fi>

src/components/views/groups/GroupMemberInfo.js

@@ -69,6 +69,7 @@ module.exports = withMatrixClient(React.createClass({
         Modal.createDialog(ConfirmUserActionDialog, {
             groupMember: this.props.groupMember,
             action: _t('Remove from group'),
+            title: _t('Remove this user from group?'),
             danger: true,
             onFinished: (proceed) => {
                 if (!proceed) return;