pkgupdate: fix too verbose output

Silence a message displayed that would trigger an extra email while
nothing happened

From Steven Shockley

pkgupdate

@@ -67,7 +67,7 @@ do_http() {
 }
 
 do_https() {
-    echo "Updating using $1 protocol"
+    silent "Updating using $1 protocol"
     check_cache
     pkg_add -u 2>&1 | grep -v "^Couldn't find updates for "
 }