Register SERVER_H2_MAX_CONCURRENT_STREAMS with default of 100

Moves the setting from a hidden getattr fallback to a proper registered
setting in global_settings.py. Default of 100 matches the HTTP/2 spec
recommendation and the h2 library's own internal default.

Author: davegaeddert

plain/plain/runtime/global_settings.py

@@ -192,6 +192,7 @@
 SERVER_GRACEFUL_TIMEOUT: int = 30
 SERVER_SENDFILE: bool = True
 SERVER_CONNECTIONS: int = 1000
+SERVER_H2_MAX_CONCURRENT_STREAMS: int = 100
 
 # MARK: Preflight Checks
 

plain/plain/server/http/h2.py

@@ -318,14 +318,11 @@ async def async_handle_h2_connection(
 
     from plain.runtime import settings
 
-    # Configure max concurrent streams if set
-    max_streams = getattr(settings, "SERVER_H2_MAX_CONCURRENT_STREAMS", None)
-    if max_streams:
-        conn.update_settings(
-            {
-                h2.settings.SettingCodes.MAX_CONCURRENT_STREAMS: max_streams,
-            }
-        )
+    conn.update_settings(
+        {
+            h2.settings.SettingCodes.MAX_CONCURRENT_STREAMS: settings.SERVER_H2_MAX_CONCURRENT_STREAMS,
+        }
+    )
 
     scheme = "https" if is_ssl else "http"
     max_body = settings.DATA_UPLOAD_MAX_MEMORY_SIZE or _H2_BODY_FALLBACK