merge from release_v4.0.2

src/main/java/cn/com/qmth/examcloud/bridge/BridgeApp.java

@@ -25,7 +25,7 @@ public class BridgeApp {
 	static {
 		String runtimeLevel = System.getProperty("log.commonLevel");
 		if (null == runtimeLevel) {
-			System.setProperty("log.commonLevel", "DEBUG");
+			System.setProperty("log.commonLevel", "INFO");
 		}
 	}