[grilo/0.2.x] build: Fail when library dependencies are missing

[Juan A. Suárez Romero <jasuarez src gnome org>]

commit 663d75cc3d3973302d175e9accb85db049b171bc
Author: Bastien Nocera <hadess hadess net>
Date:   Wed Sep 23 11:35:04 2015 +0200

    build: Fail when library dependencies are missing
    
    When --disable-grl-pls or --disable-grl-net is not passed, fail so that
    users know that those internal libraries are strongly recommended.
    
    See https://bugzilla.gnome.org/show_bug.cgi?id=755367

 configure.ac |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 087b697..6d606af 100644
--- a/configure.ac
+++ b/configure.ac
@@ -174,6 +174,7 @@ AC_ARG_ENABLE([grl_net],
         [
                 case "$enableval" in
                      yes)
+                     auto)
                         if test "x$HAVE_LIBSOUP" = "xno"; then
                            AC_MSG_ERROR([libsoup-2.4 not found, install it or use --disable-grl-net])
                         fi
@@ -198,6 +199,7 @@ AC_ARG_ENABLE([grl_pls],
         [
                 case "$enableval" in
                      yes)
+                     auto)
                         if test "x$HAVE_TOTEM_PL_PARSER" = "xno"; then
                            AC_MSG_ERROR([totem-pl-parser not found, install it or use --disable-grl-pls])
                         fi