ami: parse message contain newline

[wenerme]

[wenerme]

no way to proper handle multiline, but join the final OK to last value

Event: SMSSendStatus
Privilege: system,all
Board: 1
Channel: 4
Destination: 123
TXT: OK?
YES: NO
OK
Status: SUCCESS

[wenerme]

Can do event based last attr check to support complex multi line, like SMSSendStatus, the last line is Status