[1.4.x] PATCH: base64 encoding

[KAZ@JAPAN]

Hello

Because I am weak in English, prose may be improper, but please overlook it.

The phenomenon that a zabbix agent down after one day continued.
As a result of having tried it in various ways, I understood that I occurred when watched log file became it one line more than 20,000 bytes.

I examined a program.
And I understood that there was a problem to base64 encoding.

1) Data went away 4/3 times and caused overflow.
2) It caused 1 byte, overflow to add '\0' to the terminal of data.

I changed a program to seem to be a problem.
It was gone that a zabbix agent down.

[KAZ@JAPAN]

It was an unjust patch.

I examined a program.
And I understood that there was a problem to base64 encoding.

1) Data went away 4/3 times and caused overflow.
2) It caused 1 byte, overflow to add '\0' to the terminal of data.

I changed a program to seem to be a problem.
It was gone that a zabbix agent down.

The patch which I uploaded had the point where movement was funny last time.

I upload the patch which repaired it.