client/remote: add support to specify port number

this adds the ability to add port numbers in the backup repo spec
as well as remotes, so that user that are behind a
NAT/Firewall/Reverse proxy can still use it

also adds some explanation and examples to the docs to make it clearer
for h2 client i left the localhost:8007 part, since it is not
configurable where we bind to

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>

src/config/remote.rs

@@ -39,6 +39,11 @@ pub const REMOTE_PASSWORD_SCHEMA: Schema = StringSchema::new("Password or auth t
         host: {
             schema: DNS_NAME_OR_IP_SCHEMA,
         },
+        port: {
+            optional: true,
+            description: "The (optional) port",
+            type: u16,
+        },
         userid: {
             type: Userid,
         },
@@ -58,6 +63,8 @@ pub struct Remote {
     #[serde(skip_serializing_if="Option::is_none")]
     pub comment: Option<String>,
     pub host: String,
+    #[serde(skip_serializing_if="Option::is_none")]
+    pub port: Option<u16>,
     pub userid: Userid,
     #[serde(skip_serializing_if="String::is_empty")]
     #[serde(with = "proxmox::tools::serde::string_as_base64")]