Revert "Only build manual pages in maintainer mode"

This reverts commit cc42bd31.

For some reason Travis CI jobs use autogen.sh and don't build with all
the bells and whistles we expect developers to work with. Despite the
explicit mention in autogen.des:

    # Use this when doing code development

Some of our continuous integration doesn't emulate this properly. At
least on the VTEST and CircleCI sides we do things as expected. I will
reintroduce this change later when Travis CI is ready to take it.

configure.ac

@@ -37,7 +37,6 @@ CC="$PTHREAD_CC"
 
 AC_PROG_INSTALL
 
-AM_COND_IF([MAINTAINER_MODE], [dnl
 AC_ARG_WITH([rst2man],
   AS_HELP_STRING([--with-rst2man=PATH], [Location of rst2man (auto)]),
   [RST2MAN="$withval"],
@@ -48,7 +47,6 @@ if test "x$RST2MAN" = "xno"; then
   AC_MSG_ERROR(
     [rst2man is needed to build Varnish, please install python3-docutils.])
 fi
-])dnl AM_COND_IF MAINTAINER_MODE
 
 AC_ARG_WITH([sphinx-build],
   AS_HELP_STRING([--with-sphinx-build=PATH], [Location of sphinx-build (auto)]),

man/Makefile.am

@@ -24,9 +24,8 @@ dist_man_MANS = \
 	vmod_unix.3 \
 	vmod_proxy.3
 
-MAINTAINERCLEANFILES = $(dist_man_MANS)
+CLEANFILES = $(dist_man_MANS)
 
-if MAINTAINER_MODE
 RST2ANY_FLAGS = --halt=2
 
 BUILD_MAN = $(AM_V_GEN) $(RST2MAN) $(RST2ANY_FLAGS)
@@ -121,4 +120,3 @@ vmod_proxy.3: $(top_builddir)/lib/libvmod_proxy/vmod_proxy.man.rst
 	$(BUILD_MAN) $? $@
 
 .NOPATH: $(dist_man_MANS)
-endif # MAINTAINER_MODE