Adjusted the logic of the page up/down keys in multiline
Adjusted the logic of the page up/down keys in multiline

monkeysecurity/npyscreen,kmonsoor/npyscreen,C-Blu/npyscreen,t1g0r/npyscreen,kmonsoor/npyscreen,umars/npyscreen,dhwright25/npyscreen,t1g0r/npyscreen,monkeysecurity/npyscreen,kmonsoor/npyscreen,monkeysecurity/npyscreen,umars/npyscreen,d33tah/npyscreen,dhwright25/npyscreen,C-Blu/npyscreen,dhwright25/npyscreen,d33tah/npyscreen,kmonsoor/npyscreen,C-Blu/npyscreen,t1g0r/npyscreen,t1g0r/npyscreen,umars/npyscreen,C-Blu/npyscreen,monkeysecurity/npyscreen,umars/npyscreen