xfwm4-themes: Drop unnecessary SRC_URI[md5sum]

Signed-off-by: Jason Schonberg <schonm@gmail.com>
Signed-off-by: Khem Raj <raj.khem@gmail.com>

meta-xfce/recipes-art/xfwm4-themes/xfwm4-themes_4.10.0.bb

@@ -6,7 +6,6 @@ LIC_FILES_CHKSUM = "file://COPYING;md5=d32239bcb673463ab874e80d47fae504"
 inherit xfce
 
 SRC_URI = "http://archive.xfce.org/src/art/${BPN}/${@'${PV}'[0:4]}/${BP}.tar.bz2"
-SRC_URI[md5sum] = "eaa58362053a3549c8be0b32efd3c54f"
 SRC_URI[sha256sum] = "3214d5f00e9703b5e8c9e7c3287d606dedec7285ceb4d5db332e93ada66fd575"
 
 # using xfwm4-theme as in xfwm4 might cause warnings of packages supplied by