build: use `--enable-XYZ` options for output plugins

build: use `--enable-XYZ` options for output plugins

Currently, we use `AC_ARG_WITH` for output plugins.  However, this is
not consistent with the input plugins, which use `AC_ARG_ENABLE`, and in
some cases (dbi, mysql, pgsql) the macro calls in configure.ac conflict
with others in acinclude.m4.  Use `AC_ARG_ENABLE` instead and change the
name of the option for the JSON plugin from `jansson` to `json`.

Fixes: 51ba7aec8951 ("Fix automagic support of dbi, pcap and sqlite3")
Fixes: c61c05c2d050 ("configure.ac: Add --without-{mysql,pgsql}")
Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>