fix: backward compatibility w/ DHPARAM_GENERATION

Also use true rather than 1 to stay consistent
with other boolean environment variables

test/test_ssl/test_dhparam.py

@@ -189,6 +189,16 @@ def test_can_skip_dhparam(docker_compose):
 
     cannot_negotiate_dhe_ciphersuite(sut_container)
 
+def test_can_skip_dhparam_backward_compatibility(docker_compose):
+    container_name="dh-skip-backward"
+    sut_container = docker_client.containers.get(container_name)
+    assert sut_container.status == "running"
+    
+    assert_log_contains("Warning: The DHPARAM_GENERATION environment variable is deprecated, please consider using DHPARAM_SKIP set to true instead.", container_name)
+    assert_log_contains("Skipping Diffie-Hellman parameters setup.", container_name)
+
+    cannot_negotiate_dhe_ciphersuite(sut_container)
+
 
 def test_web5_https_works(docker_compose, nginxproxy):
     r = nginxproxy.get("https://web5.nginx-proxy.tld/port", allow_redirects=False)

test/test_ssl/test_dhparam.yml

@@ -41,6 +41,13 @@ with_custom_file:
 with_skip:
   container_name: dh-skip
   environment:
-    - DHPARAM_SKIP=1
+    - DHPARAM_SKIP=true
+  image: *img-nginxproxy
+  volumes: *vols-common
+
+with_skip_backward:
+  container_name: dh-skip-backward
+  environment:
+    - DHPARAM_GENERATION=false
   image: *img-nginxproxy
   volumes: *vols-common