swupdate: remove unecessery line

Author: embetrix

recipes-support/swupdate/swupdate_%.bbappend

@@ -42,7 +42,6 @@ do_install:append() {
     if [ "${SWUPDATE_SIGNING}" = "CMS" ] && [ -n "${SWUPDATE_CMS_CERT}" ]; then
         install -d ${D}${sysconfdir}/swupdate/
         cms_bundle="x509_swupdate.pem"
-        : > ${D}${sysconfdir}/swupdate/${cms_bundle}
         for cms_cert in ${SWUPDATE_CMS_CERT}; do
             cat "${cms_cert}" >> ${D}${sysconfdir}/swupdate/${cms_bundle}
         done