[empathy] use the plugindir pc variable from MC

[Guillaume Desmottes <gdesmott src gnome org>]

commit 4b0430db4bf7cdbef60290bdcca94bd1e5cf05d3
Author: Guillaume Desmottes <guillaume desmottes collabora co uk>
Date:   Tue Oct 22 11:36:34 2013 +0200

    use the plugindir pc variable from MC
    
    The whole point of this variable is to give us the path where plugins are
    supposed to be installed. We should just use it instead of re-implementing it
    assuming the location.

 configure.ac |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index b0a4b80..9c127ed 100644
--- a/configure.ac
+++ b/configure.ac
@@ -591,7 +591,7 @@ AM_CONDITIONAL(HAVE_UOA, test "x$have_uoa" = "xyes")
 
 if test "x$have_uoa" = "xyes" -o "x$have_goa" = "xyes"; then
    AC_MSG_CHECKING([Mission Control plugins dir])
-   MISSION_CONTROL_PLUGINS_DIR=${libdir}/mission-control-plugins.`pkg-config --variable=MCP_ABI_VERSION 
mission-control-plugins`
+   MISSION_CONTROL_PLUGINS_DIR=`pkg-config --define-variable=libdir='${libdir}' --variable=plugindir 
mission-control-plugins`
 
    AC_MSG_RESULT([$MISSION_CONTROL_PLUGINS_DIR])
    AC_SUBST(MISSION_CONTROL_PLUGINS_DIR)