python已经升级到2.78可是还是不能升级
`
[root@seafile upgrade]# python -V
Python 2.7.8
[root@seafile upgrade]# ./upgrade_5.0_5.1.sh
This script would upgrade your seafile server from 5.0 to 5.1
Press [ENTER] to contiune
Can’t find a python executable of version 2.7 or above in PATH
Install python 2.7+ before continue.
Or if you installed it in a non-standard PATH, set the PYTHON enviroment varirable to it
`