Use local LoggerContext in Log4jLog when static field not initialized…

… yet

Closes spring-projectsgh-24440

spring-jcl/src/main/java/org/apache/commons/logging/LogAdapter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2020 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -157,7 +157,12 @@ private static class Log4jLog implements Log, Serializable {
 		private final ExtendedLogger logger;
 
 		public Log4jLog(String name) {
-			this.logger = loggerContext.getLogger(name);
+			LoggerContext context = loggerContext;
+			if (context == null) {
+				// Circular call in early-init scenario -> static field not initialized yet
+				context = LogManager.getContext(Log4jLog.class.getClassLoader(), false);
+			}
+			this.logger = context.getLogger(name);
 		}
 
 		@Override