Bugix: Do not try to resolve ip addreses when adding a remote backup server

Fixes issue hestiacp#569

Author: Lupul

CHANGELOG.md

@@ -35,6 +35,7 @@ All notable changes to this project will be documented in this file.
 - Performance: Do not resolve ip when listing iptables rules. Server tab could take multiple minutes to load in some cases.
 - Update jQuery to 3.4.1 and adjust includes.
 - Fixed cronjob issue with sftp jail due to missing user.
+- Fixed issue #569 Remote backup hostname would reject ip addr without reverse dns (PTR record)
 
 ## [1.0.5] - 2019-08-06 - Hotfix
 ### Bugfixes

bin/v-add-backup-host

@@ -99,8 +99,10 @@ if [ "$type" != 'local' ];then
         which expect >/dev/null 2>&1
         check_result $? "expect command not found"  $E_NOTEXIST
     fi
-    host "$host" >/dev/null 2>&1
-    check_result $? "host connection failed" "$E_CONNECT"
+    if ! (is_ip_format_valid "$host" >/dev/null); then
+        host "$host" >/dev/null 2>&1
+        check_result $? "host connection failed" "$E_CONNECT"
+    fi
 fi
 
 # Perform verification if read-only mode is enabled