prosody: add ability to customize JWT signature type

Fixes: #1771

docker-compose.yml

@@ -232,6 +232,7 @@ services:
             - JWT_ALLOW_EMPTY
             - JWT_AUTH_TYPE
             - JWT_ENABLE_DOMAIN_VERIFICATION
+            - JWT_SIGN_TYPE
             - JWT_TOKEN_AUTH_MODULE
             - MATRIX_UVS_URL
             - MATRIX_UVS_ISSUER

prosody/rootfs/defaults/conf.d/jitsi-meet.cfg.lua

@@ -134,6 +134,9 @@ VirtualHost "jigasi.meet.jitsi"
       "muc_password_check";
     }
     authentication = "token"
+    {{ if .Env.JWT_SIGN_TYPE }}
+       signature_algorithm = "{{ .Env.JWT_SIGN_TYPE }}"
+    {{ end -}}
     app_id = "jitsi";
     asap_key_server = "https://jaas-public-keys.jitsi.net/jitsi-components/prod-8x8"
     asap_accepted_issuers = { "jaas-components" }