librest: remove spurious build dependencies

These are not dependencies of librest 0.8.1. I imagine they ended up in
this recipe when the latest version was downgraded back to 0.8.1 and the
dependencies not reviewed.

Signed-off-by: Ross Burton <ross.burton@arm.com>
Signed-off-by: Khem Raj <raj.khem@gmail.com>

meta-gnome/recipes-gnome/rest/librest_0.8.1.bb

@@ -4,13 +4,10 @@ LICENSE = "LGPL-2.1-only"
 LIC_FILES_CHKSUM = "file://COPYING;md5=2d5025d4aa3495befef8f17206a5b0a1"
 
 DEPENDS = " \
-    gi-docgen \
-    gi-docgen-native \
     glib-2.0 \
     glib-2.0-native \
-    json-glib \
     libsoup-2.4 \
-    libxml2-native \
+    libxml2 \
 "
 
 GNOMEBASEBUILDCLASS = "autotools"