升级后无法访问，仔细检查过程，在运行upgrade命令时出现如下错误：
[seafile@centos7 upgrade]$ ./upgrade_6.3_7.0.sh
This script would upgrade your seafile server from 6.3 to 7.0
Press [ENTER] to contiune
Updating seafile/seahub database …
[INFO] You are using MySQL
[INFO] updating ccnet database…
[INFO] updating seafile database…
/opt/seafile/seafile-pro-server-7.0.3/upgrade/db_update_helper.py:354: Warning: Table ‘RepoSyncError’ already exists
cursor.execute(sql)
/opt/seafile/seafile-pro-server-7.0.3/upgrade/db_update_helper.py:354: Warning: Table ‘WebUploadTempFiles’ already exists
cursor.execute(sql)
[INFO] updating seahub database…
[WARNING] Failed to execute sql: (1091, “Can’t DROP ‘profile_profile_contact_email_0975e4bf_uniq’; check that column/key exists”)
Done
migrating avatars …
Done
updating /opt/seafile/seafile-server-latest symbolic link to /opt/seafile/seafile-pro-server-7.0.3 …