Adjust apache2 start routine for ubuntu 20.04.

install/hst-install-ubuntu.sh

@@ -1178,9 +1178,9 @@ if [ "$apache" = 'yes' ]; then
 
     if [ "$release" != '20.04' ]; then
         update-rc.d apache2 defaults > /dev/null 2>&1
+        systemctl start apache2 >> $LOG
+        check_result $? "apache2 start failed"
     fi
-    systemctl start apache2 >> $LOG
-    check_result $? "apache2 start failed"
 else
     update-rc.d apache2 disable > /dev/null 2>&1
     systemctl stop apache2 > /dev/null 2>&1