..F....... [ZBX-8850] Fix fatal errors in graph generation when there is no data and ZBX_UNITS_ROUNDOFF_LOWER_LIMIT is set to "2" (default is "6") by hard-coding value "6" as rounding parameter in convertToBase1024() function.

git-svn-id: svn://svn.zabbix.com/trunk@50478 f4e7fd02-d210-4e34-a1e0-d4093fb66cc2