Remove unneeded fs.file-max setting from sysctl tuning file

The kernel (since at least some 2.6 release) automatically sets a sane value
for fs.file-max based on the amount of memory installed in that system. That
value (around 100 file descriptors per 1MB of RAM) is usually much higher than
the value (65535) this template was trying to set.
Merge pull request #191 from rhafer/fix/10gbe-tuning

Remove unneeded fs.file-max setting from sysctl tuning file