[aranea] install plugins in datadir, even when using --enable-site-packages si Gajim can find them.

configure.ac

@@ -47,12 +47,12 @@ AC_ARG_ENABLE(site-packages,
 instead of DATADIR/gajim/src.])]
 ,
 AC_SUBST([gajim_srcdir], [\${pkgpythondir}])
-AC_SUBST([gajim_pluginsdir], [\${pkgpythondir}])
 ,
 AC_SUBST([gajim_srcdir], [\${datadir}/\${PACKAGE}/src])
-AC_SUBST([gajim_pluginsdir], [\${datadir}/\${PACKAGE}/plugins])
 )
 
+AC_SUBST([gajim_pluginsdir], [\${datadir}/\${PACKAGE}/plugins])
+
 AS_AC_EXPAND(GAJIM_SRCDIR, "${gajim_srcdir}")
 AS_AC_EXPAND(PKGDATADIR, "${datadir}/${PACKAGE}")
 AS_AC_EXPAND(DOCDIR, "${docdir}")