fix write permission when updating github cache

deb-get

@@ -168,7 +168,7 @@ function get_github_releases() {
             fancy_message info "Updating ${CACHE_FILE}"
             local URL="https://api.github.com/repos/${1}/releases${2:+/$2}"
             wgetcmdarray=(wget  "${HEADERPARAM}" "${HEADERAUTH}" -q --no-use-server-timestamps "${URL}" -O- )
-            ${ELEVATE} "${wgetcmdarray[@]}" | sed '/browser_download/!d;/\.deb/!d' >  "${CACHE_FILE}" || ( fancy_message warn "Updating ${CACHE_FILE} failed." )
+            "${wgetcmdarray[@]}" | sed '/browser_download/!d;/\.deb/!d' | ${ELEVATE} tee "${CACHE_FILE}" > /dev/null || ( fancy_message warn "Updating ${CACHE_FILE} failed." )
             if [ -f "${CACHE_FILE}" ] && grep "API rate limit exceeded" "${CACHE_FILE}"; then
                 fancy_message warn "Updating ${CACHE_FILE} exceeded GitHub API limits. Deleting it."
                 ${ELEVATE} rm "${CACHE_FILE}" 2>/dev/null