fix(xen-api): fix HTTP/2 for server behind HTTP proxy (#10507)

Introduced by 11eed70
fix Forum#12502

CHANGELOG.unreleased.md

@@ -15,6 +15,8 @@
 
 > Users must be able to say: "I had this issue, happy to know it's fixed"
 
+- [Servers] Fix servers stuck in `Connecting` state when using an HTTPS proxy that support HTTP/2 ([Forum#12502](https://xcp-ng.org/forum/topic/12502/xoa-6.9-update)) (PR [#10507](https://github.com/vatesfr/xen-orchestra/pull/10507))
+
 ### Packages to release
 
 > When modifying a package, add it here with its release type.
@@ -31,4 +33,6 @@
 
 <!--packages-start-->
 
+- xen-api patch
+
 <!--packages-end-->

packages/xen-api/index.mjs

@@ -266,7 +266,9 @@ export class Xapi extends EventEmitter {
       this._undiciDispatcher = new ProxyAgent({
         ...dispatcherOpts,
 
-        proxyTls: tlsOpts,
+        // the `allowH2` option above does not apply to the connection with the
+        // HTTP proxy: undici cannot tunnel through HTTP/2 and reconnects endlessly
+        proxyTls: { ...tlsOpts, allowH2: false },
         requestTls: tlsOpts,
         token,
         uri,