Fix typo and encoding.

     jchampion: r1702948 doesn't quite work as advertised. -Werror is never

                added to CFLAGS because when combined with -Wstrict-prototypes,

                the AC_LANG_PROGRAM won't compile (it uses a bare main()).

     ylavic: Maybe to -Werror case could be handled later, for now this series

             avoids a lot of "warning: ‘aplog_module_index’ defined but not

     ylavic: Maybe the -Werror case could be handled later, for now this series

             avoids a lot of "warning: 'aplog_module_index' defined but not

             used [-Wunused-const-variable=]" thanks to AP_MAYBE_UNUSED.

  *) core: avoid adding multiple subrequest filters when there are nested