xfce-dusk-gtk3: fix do_fetch error

Change the SRC_URI to the correct value due to the following error:
WARNING: xfce-dusk-gtk3-1.3-r0 do_fetch: Failed to fetch URL http://sources.openembedded.org/141404-xfce_dusk_gtk3-1_3.tar.gz;subdir=xfce-dusk-gtk3-1.3, attempting MIRRORS if available

Signed-off-by: Jiaying Song <jiaying.song.cn@windriver.com>
Signed-off-by: Armin Kuster <akuster808@gmail.com>

meta-xfce/recipes-art/xfce-dusk-gtk3/xfce-dusk-gtk3_1.3.bb

@@ -4,7 +4,7 @@ LIC_FILES_CHKSUM = "file://LICENSE;md5=8f0e2cd40e05189ec81232da84bd6e1a"
 
 inherit allarch
 
-SRC_URI = "http://sources.openembedded.org/141404-xfce_dusk_gtk3-1_3.tar.gz;subdir=${BPN}-${PV}"
+SRC_URI = "https://downloads.yoctoproject.org/mirror/sources/141404-xfce_dusk_gtk3-1_3.tar.gz;subdir=${BPN}-${PV}"
 SRC_URI[md5sum] = "b3ad37ad8173b14ec090e60a80e65d8f"
 SRC_URI[sha256sum] = "bfa8a88607d1a1da5bd0b9e4e075767c54400a3c5a0fae88b619ed71532f30b4"