fix(xo-web): don't add servers with empty httpProxy

Fixes #6656

Introduced by 2412f8b1e

This commit also contains a change in `xo-server` to properly handle servers in database that have this problematic entries.

CHANGELOG.unreleased.md

@@ -12,6 +12,7 @@
 > Users must be able to say: “I had this issue, happy to know it's fixed”
 
 - [Import VM] fix invalid parameters when importing a VM from VMware [Forum#6714](https://xcp-ng.org/forum/topic/6714/vmware-migration-tool-we-need-your-feedback/143) (PR [#6696](https://github.com/vatesfr/xen-orchestra/pull/6696))
+- [Backup] Fix _A "socket" was not created for HTTP request before 300000ms_ error [Forum#59163](https://xcp-ng.org/forum/post/59163) [#6656](https://github.com/vatesfr/xen-orchestra/issues/6656)
 
 ### Packages to release
 

packages/xo-server/src/models/server.mjs

@@ -29,6 +29,11 @@ export class Servers extends Collection {
         delete server.error
       }
       server.readOnly = server.readOnly === 'true'
+
+      // see https://github.com/vatesfr/xen-orchestra/issues/6656
+      if (server.httpProxy === '') {
+        delete server.httpProxy
+      }
     })
 
     return servers

packages/xo-web/src/common/xo/index.js

@@ -612,7 +612,7 @@ export const addServer = (host, username, password, label, allowUnauthorized, ht
   _call('server.add', {
     allowUnauthorized,
     host,
-    httpProxy,
+    httpProxy: httpProxy || undefined,
     label,
     password,
     username,