false positive change detection on sysctl values output containing tabs

[schlitzered]

hi,

some sysctl values return spaces, this causes false positive change detection.

this pull requests solves this issue, by transforming tabs to two spaces.

#72

an example sysctl value that suffers from this issue is: net.ipv4.ping_group_range

the value of net.ipv4.ping_group_range has tabs in it.