[PR #5662/471f523f backport][stable-6] redhat_subscription: add server_proxy_scheme parameter (#5671)

redhat_subscription: add `server_proxy_scheme` parameter (#5662)

Add the `server_proxy_scheme` parameter to configure the scheme used for
the proxy server. This completes the configuration parameters for the
proxy server.

(cherry picked from commit 471f523f53)

Co-authored-by: Pino Toscano <ptoscano@redhat.com>

plugins/modules/redhat_subscription.py

@@ -70,6 +70,11 @@ options:
         description:
             - Specify an HTTP proxy hostname.
         type: str
+    server_proxy_scheme:
+        description:
+            - Specify an HTTP proxy scheme, for example C(http) or C(https).
+        type: str
+        version_added: 6.2.0
     server_proxy_port:
         description:
             - Specify an HTTP proxy port.
@@ -806,6 +811,7 @@ def main():
             'consumer_id': {},
             'force_register': {'default': False, 'type': 'bool'},
             'server_proxy_hostname': {},
+            'server_proxy_scheme': {},
             'server_proxy_port': {},
             'server_proxy_user': {},
             'server_proxy_password': {'no_log': True},