test: removes uncessary ifDefine at 10-tfn-cache.t

IfDefines such as: <IfDefine MODSEC_2.5> are just compatible with Apache a
solution to check if some resource is available or not have to be developed
to be used in situations like that. This commit just removes the IfDefine.
nginx: Considering modsec state before apply any rules

For some reason the state of modsec (enable, disable or detecting only) was not
being checked under certain circumstances. For instance, while reading the
body. This was leading ModSecurity to fail and consequently nginx. This patch
added the to standalone implementation mechanism to verify the state that is now
verified under the nginx module.