新建用户时限制用户全名第一个字符不可以是空格。

Log: 修复新建帐户全名可以为连续空格的问题。
Bug: https://pms.uniontech.com/zentao/bug-view-49133.html
Change-Id: I3f5b47c9fc920821417451cc129b8351ae3bc0df
Reviewed-on: http://gerrit.uniontech.com/c/dde-control-center/+/6127
Reviewed-by: <mailman@uniontech.com>
Reviewed-by: lvpeilong <lvpeilong@uniontech.com>
Tested-by: <mailman@uniontech.com>