Fix sftp server validation check, thanks to @dbannik!

CHANGELOG.md

@@ -14,6 +14,7 @@ All notable changes to this project will be documented in this file.
 - Enable hsts and force ssl on v-add-letsencrypt-host.
 - Prevent login action for webmail in list user view.
 - Remove hardcoded mail in helo data (cosmetic fix).
+- Fix sftp server validation check, thanks to @dbannik!
 
 ## [1.0.4] - 2019-07-09 - Hotfix
 ### Bugfixes

bin/v-add-backup-host

@@ -38,8 +38,7 @@ EOF
 sftpc() {
     expect -f "-" <<EOF "$@"
         set count 0
-        spawn "/usr/bin/sftp -o StrictHostKeyChecking=no -o \
-            Port=$port '$user@$host'"
+        spawn /usr/bin/sftp -o StrictHostKeyChecking=no -o Port=$port $user@$host
         expect {
             "password:" {
                 send "$password\r"