Revert "Add warning message if the Java agent is in the class path (#3960)"

This reverts commit 85bd47b.

Author: trask

agent/agent-tooling/src/main/java/com/microsoft/applicationinsights/agent/internal/init/FirstEntryPoint.java

@@ -122,18 +122,9 @@ public void init(EarlyInitAgentConfig earlyConfig) {
         startupLogger.debug("JAVA_TOOL_OPTIONS: " + System.getenv("JAVA_TOOL_OPTIONS"));
       }
 
-      String classPath = System.getProperty("java.class.path");
-      // class path null with a Spring Boot executable JAR
-      if (classPath != null
-          // JAR name in Maven central, the user could have renamed it
-          && classPath.contains("applicationinsights-agent")) {
-        startupLogger.warn(
-            "The applicationinsights-agent JAR is in the class path. You should remove it because it could lead to unexpected results. You should configure the Java agent with -javaagent. You can also use the runtime attachment with Spring Boot applications.");
-      }
-
       if (startupLogger.isTraceEnabled()) {
         startupLogger.trace("OS: " + System.getProperty("os.name"));
-        startupLogger.trace("Classpath: " + classPath);
+        startupLogger.trace("Classpath: " + System.getProperty("java.class.path"));
         startupLogger.trace("Netty versions: " + NettyVersions.extract());
         startupLogger.trace("Env: " + findEnvVariables());
         startupLogger.trace("System properties: " + findSystemProperties());