This removes the following module hooks:
OnConfigLine()
OnWriteConfig()
OnWriteUserConfig()
OnWriteChanConfig()
Modules could use these hooks for writing/reading their own stuff to/from
znc.conf. However, no module (ever?) did this and IMHO no module should ever do
this either. Modules can save stuff via SetNV(), module arguments (SetArgs())
and in their GetSavePath().
Signed-off-by: Uli Schlachter <psychon@znc.in>
